Difference between revisions of "Placenta"

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The '''placenta''' feeds the developing baby, breathes for it and disposes of its waste.
[[Image:Human_placenta.jpg|thumb|right|A placenta (fetal aspect) with attached umbilical cord. (WC/Asturnut)]]
The '''placenta''' feeds the developing baby, breathes for it and disposes of its waste.  


=Clinical=
The organ is one that seems to be left behind; at least one review suggests it isn't done so well by general pathologists.<ref name=pmid12033960>{{Cite journal  | last1 = Sun | first1 = CC. | last2 = Revell | first2 = VO. | last3 = Belli | first3 = AJ. | last4 = Viscardi | first4 = RM. | title = Discrepancy in pathologic diagnosis of placental lesions. | journal = Arch Pathol Lab Med | volume = 126 | issue = 6 | pages = 706-9 | month = Jun | year = 2002 | doi = 10.1043/0003-9985(2002)1260706:DIPDOP2.0.CO;2 | PMID = 12033960 }}</ref>
 
''Placental pathology'' redirects to this article.
 
=Clinical=  
==Examination of the placenta==
==Examination of the placenta==
*Most placentas are ''not'' examined by a pathologist.
*Most placentas are ''not'' examined by a pathologist.
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====Most common====
====Most common====
Most common reasons for submitting a placenta to pathology:<ref>CS. 8 February 2011.</ref>
Most common reasons for submitting a placenta to pathology:<ref>Sherman C. 8 February 2011.</ref>
# Prematurity.
# Prematurity.
# PROM / possible [[chorioamnionitis]].  
# PROM / possible [[chorioamnionitis]].  
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==Abbreviations==
==Abbreviations==
*C/S = Caesarian section.
*C/S = Caesarean section.
*LSCS = lower segment C-section.
*LSCS = lower segment C-section.
*FTP = failure to progress.
*FTP = failure to progress.
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*PPROM = preterm premature ruptures of membranes.
*PPROM = preterm premature ruptures of membranes.
*IUGR = [[intrauterine growth restriction]].
*IUGR = [[intrauterine growth restriction]].
*IOL = induction of labour.


=Normal histology=
=Normal histology=
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**Focal small deposits are considered to be a normal finding - seen in ~15% of cases.<ref name=pmid21393870>{{Cite journal  | last1 = Narasimha | first1 = A. | last2 = Vasudeva | first2 = DS. | title = Spectrum of changes in placenta in toxemia of pregnancy. | journal = Indian J Pathol Microbiol | volume = 54 | issue = 1 | pages = 15-20 | month =  | year =  | doi = 10.4103/0377-4929.77317 | PMID = 21393870 |URL = http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2011;volume=54;issue=1;spage=15;epage=20;aulast=Narasimha }}</ref><ref>URL: [http://zulekhahospitals.com/uploads/files/Sub-chorionic.pdf http://zulekhahospitals.com/uploads/files/Sub-chorionic.pdf]. Accessed on: 17 August 2012.</ref>
**Focal small deposits are considered to be a normal finding - seen in ~15% of cases.<ref name=pmid21393870>{{Cite journal  | last1 = Narasimha | first1 = A. | last2 = Vasudeva | first2 = DS. | title = Spectrum of changes in placenta in toxemia of pregnancy. | journal = Indian J Pathol Microbiol | volume = 54 | issue = 1 | pages = 15-20 | month =  | year =  | doi = 10.4103/0377-4929.77317 | PMID = 21393870 |URL = http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2011;volume=54;issue=1;spage=15;epage=20;aulast=Narasimha }}</ref><ref>URL: [http://zulekhahospitals.com/uploads/files/Sub-chorionic.pdf http://zulekhahospitals.com/uploads/files/Sub-chorionic.pdf]. Accessed on: 17 August 2012.</ref>
***The pathologic counterpart of this is ''[[perivillous fibrin deposition]]''.
***The pathologic counterpart of this is ''[[perivillous fibrin deposition]]''.
Image:
*[http://www.ijpmonline.org/viewimage.asp?img=IndianJPatholMicrobiol_2011_54_1_15_77317_u5.jpg Subchorionic fibrin deposition (ijpmonline.org)].


==Common terms==
==Common terms==
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===Linear regression - placental mass-gestational age===
===Linear regression - placental mass-gestational age===
Based on the table in the AFIP book<ref>AFIP Placental pathol. ISBN: 1-881041-89-1. P.312</ref> I generated the following regression lines:
Based on the table in the AFIP book<ref>AFIP Placental pathol. ISBN: 1-881041-89-1. P.312</ref> one can generate the following regression lines:
{| class="wikitable"
{| class="wikitable"
| ||'''50%''' ||'''10%''' ||'''90%'''
| ||'''50%''' ||'''10%''' ||'''90%'''
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*Is it required?
*Is it required?
**Sebire and Fox have advocated abandoning the practise of obtaining a placental mass, due to the large number of uncontrolled variables inherent in these measures.  Instead, they have advocated using mushy descriptors such as "small", "average" and "large", which require experience in examining the organ.<ref>{{cite book |author= Fox, Harold; Sebire, Neil J. |title=[http://www.amazon.com/Pathology-Placenta-Major-Problems/dp/1416025928/ref=sr_1_fkmr0_1?ie=UTF8&qid=1297259619&sr=1-1-fkmr0 Pathology of the Placenta (Major Problems in Pathology)]|publisher=Saunders |location= |year=2007 |pages= 559-561 |edition=3rd |isbn=978-1416025924 |oclc= |doi= |accessdate=}}</ref>   
**Sebire and Fox have advocated abandoning the practise of obtaining a placental mass, due to the large number of uncontrolled variables inherent in these measures.  Instead, they have advocated using mushy descriptors such as "small", "average" and "large", which require experience in examining the organ.<ref>{{cite book |author= Fox, Harold; Sebire, Neil J. |title=[http://www.amazon.com/Pathology-Placenta-Major-Problems/dp/1416025928/ref=sr_1_fkmr0_1?ie=UTF8&qid=1297259619&sr=1-1-fkmr0 Pathology of the Placenta (Major Problems in Pathology)]|publisher=Saunders |location= |year=2007 |pages= 559-561 |edition=3rd |isbn=978-1416025924 |oclc= |doi= |accessdate=}}</ref>   
***In the context of quality, a measure (even if somewhat flawed), is almost certainly more reproducible than arbitrary descriptors which require experience and a continuing case volume to calibrate.
***In the context of quality, a measure (even if somewhat flawed) is probably more reproducible and objective than arbitrary descriptors which require experience and a continuing case volume to calibrate.


===Placentomegaly===
===Placentomegaly===
*[[AKA]] ''large placenta''.
Associations:<ref>URL: [http://quizlet.com/5793113/ob-flash-cards/ http://quizlet.com/5793113/ob-flash-cards/]. Accessed on: 13 January 2012.</ref>
Associations:<ref>URL: [http://quizlet.com/5793113/ob-flash-cards/ http://quizlet.com/5793113/ob-flash-cards/]. Accessed on: 13 January 2012.</ref>
*Maternal diabetes - esp. poorly controlled.<ref name=pmid2771897>{{Cite journal  | last1 = Clarson | first1 = C. | last2 = Tevaarwerk | first2 = GJ. | last3 = Harding | first3 = PG. | last4 = Chance | first4 = GW. | last5 = Haust | first5 = MD. | title = Placental weight in diabetic pregnancies. | journal = Placenta | volume = 10 | issue = 3 | pages = 275-81 | month =  | year =  | doi =  | PMID = 2771897 }}</ref>
*Maternal [[diabetes]] - esp. poorly controlled.<ref name=pmid2771897>{{Cite journal  | last1 = Clarson | first1 = C. | last2 = Tevaarwerk | first2 = GJ. | last3 = Harding | first3 = PG. | last4 = Chance | first4 = GW. | last5 = Haust | first5 = MD. | title = Placental weight in diabetic pregnancies. | journal = Placenta | volume = 10 | issue = 3 | pages = 275-81 | month =  | year =  | doi =  | PMID = 2771897 }}</ref>
*Maternal [[anemia]]/low maternal iron stores.<ref>{{Cite journal  | last1 = Hindmarsh | first1 = PC. | last2 = Geary | first2 = MP. | last3 = Rodeck | first3 = CH. | last4 = Jackson | first4 = MR. | last5 = Kingdom | first5 = JC. | title = Effect of early maternal iron stores on placental weight and structure. | journal = Lancet | volume = 356 | issue = 9231 | pages = 719-23 | month = Aug | year = 2000 | doi =  | PMID = 11085691 }}</ref>
*Maternal [[anemia]]/low maternal iron stores.<ref>{{Cite journal  | last1 = Hindmarsh | first1 = PC. | last2 = Geary | first2 = MP. | last3 = Rodeck | first3 = CH. | last4 = Jackson | first4 = MR. | last5 = Kingdom | first5 = JC. | title = Effect of early maternal iron stores on placental weight and structure. | journal = Lancet | volume = 356 | issue = 9231 | pages = 719-23 | month = Aug | year = 2000 | doi =  | PMID = 11085691 }}</ref>
*Fetal malformations.
*Fetal malformations.
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===Placental growth restriction===
===Placental growth restriction===
*[[AKA]] ''placenta small for gestational age''.
*[[AKA]] ''placenta small for gestational age''.
Association:
*''Small placenta'' redirects here.
Associations:
*Maternal vascular disease, e.g. [[hypertrophic decidual vasculopathy|hypertension]].
*Maternal vascular disease, e.g. [[hypertrophic decidual vasculopathy|hypertension]].
*Fetal malformations.
*Fetal malformations.
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====Sign out====
====Sign out====
<pre>
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- PLACENTA SMALL FOR GESTATIONAL AGE (160 GRAMS -- TRIMMED, POST-FIXATION WEIGHT).
- PLACENTA SMALL FOR GESTATIONAL AGE (160 GRAMS -- TRIMMED, POST-FIXATION WEIGHT).
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
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===C-section===
===C-section===
<pre>
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES,CAESARIAN SECTION:
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CAESAREAN SECTION:
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
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=Cord pathology=
=Cord pathology=
*Two vessel cord.
*[[Two vessel cord]].
*Hypercoiling/Hypocoiling.
*Hypercoiling/Hypocoiling.
*Abnormal insertion.
*Abnormal insertion.
*Cord knots (true vs. false).
*[[Cord knot]]s (true vs. false).
*Strictures.
*Strictures.
*Hematoma.
*Hematoma.
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*[[AKA]] ''two vessel cord''.
*[[AKA]] ''two vessel cord''.
*[[AKA]] ''single umbilical artery''.
*[[AKA]] ''single umbilical artery''.
 
{{Main|Two vessel umbilical cord}}
===Associations===
*Associated with congenital abnormalities, esp. cardiac - '''key point'''.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref>
**Thought to be an acquired defect (as prevalence is lower early in gestation).
*May be seen in association of other cord abnormalities (e.g. marginal insertion, velamentous insertion).
*In apparently well (liveborn) infants it is associated with (occult) renal abnormalities, specifically vesico-ureteric reflux; there is no evidence for other abnormalities.<ref name=pmid15613529>{{cite journal |author=Srinivasan R, Arora RS |title=Do well infants born with an isolated single umbilical artery need investigation? |journal=Arch. Dis. Child. |volume=90 |issue=1 |pages=100–1 |year=2005 |month=January |pmid=15613529 |pmc=1720078 |doi=10.1136/adc.2004.062372 |url=}}</ref>
*Associated with maternal [[diabetes]].<ref name=pmid7997408>{{cite journal |author=Lilja M |title=Infants with single umbilical artery studied in a national registry. 3: A case control study of risk factors |journal=Paediatr Perinat Epidemiol |volume=8 |issue=3 |pages=325–33 |year=1994 |month=July |pmid=7997408 |doi= |url=}}</ref>
 
Image:
*[http://www.glowm.com/resources/glowm/graphics/figures/v2/1070/05b.jpg SUA (glown.com)].<ref>URL: [http://www.glowm.com/?p=glowm.cml/section_view&articleid=151 http://www.glowm.com/?p=glowm.cml/section_view&articleid=151]. Accessed on: 8 January 2011.</ref>


==Insertion==
==Insertion==
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*Increased risk of vasa previa.<ref name=pmid20872421>{{cite journal |author=Hasegawa J, Farina A, Nakamura M, ''et al.'' |title=Analysis of the ultrasonographic findings predictive of vasa previa |journal=Prenat. Diagn. |volume=30 |issue=12-13 |pages=1121–5 |year=2010 |month=December |pmid=20872421 |doi=10.1002/pd.2618 |url=}}</ref>
*Increased risk of vasa previa.<ref name=pmid20872421>{{cite journal |author=Hasegawa J, Farina A, Nakamura M, ''et al.'' |title=Analysis of the ultrasonographic findings predictive of vasa previa |journal=Prenat. Diagn. |volume=30 |issue=12-13 |pages=1121–5 |year=2010 |month=December |pmid=20872421 |doi=10.1002/pd.2618 |url=}}</ref>


==Knots==
====Sign out====
<pre>
PLACENTA, UMBILICAL CORDS AND FETAL MEMBRANES, BIRTH:
- THREE VESSEL UMBILICAL CORD WITH A VELAMENTOUS INSERTION, OTHERWISE WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS.
</pre>
 
==Umbilical knot==
*[[AKA]] ''umbilical cord knot''.
*[[AKA]] ''cord knot''.
*[[AKA]] ''true knot''.
===General===
===General===
*Prevalence ~1.25%.<ref name=pmid12012287>{{cite journal |author=Airas U, Heinonen S |title=Clinical significance of true umbilical knots: a population-based analysis |journal=Am J Perinatol |volume=19 |issue=3 |pages=127–32 |year=2002 |month=April |pmid=12012287 |doi=10.1055/s-2002-25311 |url=}}</ref><ref name=Ref_WMSP>{{Ref WMSP|464}}</ref>
*Prevalence ~1.25%.<ref name=pmid12012287>{{cite journal |author=Airas U, Heinonen S |title=Clinical significance of true umbilical knots: a population-based analysis |journal=Am J Perinatol |volume=19 |issue=3 |pages=127–32 |year=2002 |month=April |pmid=12012287 |doi=10.1055/s-2002-25311 |url=}}</ref><ref name=Ref_WMSP>{{Ref WMSP|464}}</ref>
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*Rare ~ 1/5500.
*Rare ~ 1/5500.
*Mortality ~50% is severe.
*Mortality ~50% is severe.
Image: [http://flylib.com/books/2/953/1/html/2/43%20-%20Placenta_files/DA10C43FF12.png Hematoma (flylib.com)].<ref>URL: [http://flylib.com/books/en/2.953.1.49/1/ http://flylib.com/books/en/2.953.1.49/1/]. Accessed on: 10 January 2011.</ref>


=Membranes=
=Membranes=
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==Amnion nodosum==
==Amnion nodosum==
===General===
{{Main|Amnion nodosum}}
*Associated with (long-standing) oligohydramnios.<ref>URL: [http://library.med.utah.edu/WebPath/PLACHTML/PLAC042.html http://library.med.utah.edu/WebPath/PLACHTML/PLAC042.html]. Accessed on: 12 January 2011.</ref>
*Should be separated from ''squamous metaplasia of amnion''.
 
===Gross===
Features:<ref name=pmid18081444>{{Cite journal  | last1 = Adeniran | first1 = AJ. | last2 = Stanek | first2 = J. | title = Amnion nodosum revisited: clinicopathologic and placental correlations. | journal = Arch Pathol Lab Med | volume = 131 | issue = 12 | pages = 1829-33 | month = Dec | year = 2007 | doi = 10.1043/1543-2165(2007)131[1829:ANRCAP]2.0.CO;2 | PMID = 18081444 }}</ref>
*Yellow nodules ~ 1-5 mm.
**Some think they are white.<ref>CS. 7 February 2011.</ref>
 
DDx:
*[[Squamous metaplasia of the amnion]] - large irregular patches, usu. white.
 
Images:
*[http://www.webpathology.com/image.asp?n=2&Case=659 Amnion nodosum (webpathology.com)].
*[http://www.archivesofpathology.org/action/showFullPopup?id=i1543-2165-131-12-1829-f01&doi=10.1043%2F1543-2165%282007%29131%5B1829%3AANRCAP%5D2.0.CO%3B2 Amnion nodosum & squamous metaplasia of the amnion (archivesofpathology.org)].<ref name=pmid18081444/>
<!-- annoying use of '[' and ']' - had to go find escape characters here: http://www.w3schools.com/tags/ref_urlencode.asp -->
 
===Microscopic===
Features:<ref name=pmid18081444/>
*Stratified squamous epithelium - non-keratinizing ''or'' minimal keratin.
*Amorphous acidophilic (pink) debris.
 
Note:
*Normal amnion = simple epithelium.
 
Images:
*[http://www.webpathology.com/image.asp?case=659&n=3 Amnion nodosum (webpathology.com)].
*[http://www.archivesofpathology.org/action/showFullPopup?id=i1543-2165-131-12-1829-f01&doi=10.1043%2F1543-2165%282007%29131%5B1829%3AANRCAP%5D2.0.CO%3B2 Amnion nodosum & squamous metaplasia of the amnion (archivesofpathology.org)].<ref name=pmid18081444/>
<!-- annoying use of '[' and ']' - had to go find escape characters here: http://www.w3schools.com/tags/ref_urlencode.asp -->


==Placental meconium==
==Placental meconium==
*[[AKA]] ''meconium staining''.
{{Main|Placental meconium}}
===General===
*Associated with fetal distress.
*Small amount - at term - is considered to be normal.
 
Other meconium-related pathology:
*[[Meconium peritonitis]].
*[[Meconium ileus]].
 
===Gross===
*Green/green discolourization.
 
===Microscopic===
Features:<ref>ALS. 6 Febraury 2009.</ref>
*Meconium histiocytes - '''key feature'''.
**Macrophages with brown fine granular pigment.
*Pseudostratified epithelium (amnion) - low power.
*Amnion - columnar morphology (normally cuboidal).
*"Drop-out" of individual amnion cells / loss of individual cells.
 
Time of meconium passage:<ref name=pmid2413412>{{cite journal |author=Miller PW, Coen RW, Benirschke K |title=Dating the time interval from meconium passage to birth |journal=Obstet Gynecol |volume=66 |issue=4 |pages=459–62 |year=1985 |month=October |pmid=2413412 |doi= |url=}}</ref>
*<1 h - no staining of membranes.
*1-3 h - amnion is stained.
*>3 h - chorion is stained.
 
DDx:
*Hemosiderin-laden macrophages.
**This is sorted-out with an iron stain -- see below.
 
Notes:
*The above time course is disputed - in vitro experiments suggest it is considerably longer.<ref name=pmid19031358>{{cite journal |author=Funai EF, Labowsky AT, Drewes CE, Kliman HJ |title=Timing of fetal meconium absorption by amnionic macrophages |journal=Am J Perinatol |volume=26 |issue=1 |pages=93–7 |year=2009 |month=January |pmid=19031358 |doi=10.1055/s-0028-1103028 |url=}}</ref>
 
 
Images:
*[http://commons.wikimedia.org/wiki/File:Meconium-laden_macrophages_high_mag.jpg Meconium-laden macrophages - high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Meconium-laden_macrophages_intermed_mag.jpg Meconium-laden macrophages - intermed. mag. (WC)].
 
===Special stains===
*Hemosiderin +ve in hemosiderin-laden macrophages.
*PAS +ve in meconium-laden macrophages.<ref name=pmid11268705>{{cite journal |author=Povýsil C, Bennett R, Povýsilová V |title=CD 68 positivity of the so-called meconium corpuscles in human foetal intestine |journal=Cesk Patol |volume=37 |issue=1 |pages=7–9 |year=2001 |month=January |pmid=11268705 |doi= |url=}}</ref>
 
Useful to differentiate hemosiderin-laden macrophages and meconium laden macrophages:
*Hemosiderin stain -- +ve for old blood.
**Prussian-blue stain = hemosiderin stain.<ref>{{cite journal |author=Sienko A, Altshuler G |title=Meconium-induced umbilical vascular necrosis in abortuses and fetuses: a histopathologic study for cytokines |journal=Obstet Gynecol |volume=94 |issue=3 |pages=415?0 |year=1999 |month=September |pmid=10472870 |doi= |url=}}</ref>
 
Notes:
*PAS-D -- +ve in meconium... though may rarely stain hemosiderin.
*Meconium contains bile.<ref>{{cite journal |author=Sienko A, Altshuler G |title=Meconium-induced umbilical vascular necrosis in abortuses and fetuses: a histopathologic study for cytokines |journal=Obstet Gynecol |volume=94 |issue=3 |pages=415?0 |year=1999 |month=September |pmid=10472870 |doi= |url=}}</ref>
 
===Sign out===
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- FETAL MEMBRANES WITH MECONIUM-LADEN MACROPHAGES, NEGATIVE FOR CHORIOAMNIONITIS.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS.
</pre>


==Squamous metaplasia of the amnion==
==Squamous metaplasia of the amnion==
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===Gross===
===Gross===
Features:<ref name=pmid18081444/>
Features:<ref name=pmid18081444>{{Cite journal  | last1 = Adeniran | first1 = AJ. | last2 = Stanek | first2 = J. | title = Amnion nodosum revisited: clinicopathologic and placental correlations. | journal = Arch Pathol Lab Med | volume = 131 | issue = 12 | pages = 1829-33 | month = Dec | year = 2007 | doi = 10.1043/1543-2165(2007)131[1829:ANRCAP]2.0.CO;2 | PMID = 18081444 }}</ref>
*White (or yellow) plaques - irregular outline.
*White (or yellow) plaques - irregular outline.


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===General===
===General===
*Non-specific finding.
*Non-specific finding.
*Reported in associated with congenital adrenal hyperplasia for the stem villi.<ref name=pmid11045335>{{Cite journal  | last1 = Furuhashi | first1 = M. | last2 = Oda | first2 = H. | last3 = Nakashima | first3 = T. | title = Hydrops of placental stem villi complicated with fetal congenital adrenal hyperplasia. | journal = Arch Gynecol Obstet | volume = 264 | issue = 2 | pages = 101-4 | month = Sep | year = 2000 | doi =  | PMID = 11045335 }}</ref>


===Microscopic===
===Microscopic===
Features:
Features:
*"Swiss chesse-like" appearance / bubbly appearance.
*"Swiss chesse-like" appearance / bubbly appearance.
*Usu. patchy and focal.
*Usually patchy and focal.
 
Note:
*Cistern formation is reported in the stem villi in association with congenital adrenal hyperplasia.<ref name=pmid11045335/>


DDx:  
DDx:  
**Chorioamnionitis, fetal edema, idiopathic (no cause apparent).
*[[Chorioamnionitis]].
*Fetal edema.
*Idiopathic (no cause apparent).
*[[Placental villous immaturity]].


Image:
Image:
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==Placental villous immaturity==
==Placental villous immaturity==
*[[AKA]] ''distal villous immaturity'', [[AKA]] ''villous immaturity'', [[AKA]] ''villous dysmaturity''.<ref name=Ref_Placenta_375>{{Ref Placenta|375}}</ref>
{{Main|Placental villous immaturity}}
 
===General===
Associated with:
*[[Diabetes mellitus]].<ref name=pmid1856519>{{Cite journal  | last1 = Arizawa | first1 = M. | last2 = Nakayama | first2 = M. | last3 = Kidoguchi | first3 = K. | title = [Correlation of placental villous immaturity and dysmaturity with clinical control of maternal diabetes]. | journal = Nihon Sanka Fujinka Gakkai Zasshi | volume = 43 | issue = 6 | pages = 595-602 | month = Jun | year = 1991 | doi =  | PMID = 1856519 }}</ref>
*[[Beckwith-Wiedemann syndrome]].
*Intrauterine fetal demise near term.<ref name=pmid15138817>{{Cite journal  | last1 = Stallmach | first1 = T. | last2 = Hebisch | first2 = G. | title = Placental pathology: its impact on explaining prenatal and perinatal death. | journal = Virchows Arch | volume = 445 | issue = 1 | pages = 9-16 | month = Jul | year = 2004 | doi = 10.1007/s00428-004-1032-2 | PMID = 15138817 }}</ref>
 
===Microscopic===
Features:<ref name=Ref_Placenta_375>{{Ref Placenta|375}}</ref>
*Large villi with:
**Increased number of capillaries.
**Edema.
**Macrophages.
**Large diffusion distance (vessel-to-villous surface distance large).


Images:
==Villous hypoplasia==
*[[WC]]:
*[[AKA]] ''terminal villus deficiency''.<ref name=Ref_Placenta346>{{Ref Placenta|346}}</ref>
**[http://commons.wikimedia.org/wiki/File:Placental_villous_immaturity_-_low_mag.jpg Placental villous immaturity - low mag. (WC)].
{{Main|Villous hypoplasia}}
**[http://commons.wikimedia.org/wiki/File:Placental_villous_immaturity_-_intermed_mag.jpg Placental villous immaturity - intermed. mag. (WC)].


=Diseases of the placental attachment=
=Diseases of the placental attachment=
==Placenta creta==
==Placenta creta==
*What?
Includes ''placenta accreta'', ''placenta increta'', and ''placenta percreta''.
**Trophoblastic tissue deeper than it should be.
{{Main|Placenta creta}}
*Clinical?
**Postpartum hemorrhage leading to a hysterectomy.<ref name=pmid18514815>{{Cite journal  | last1 = Tantbirojn | first1 = P. | last2 = Crum | first2 = CP. | last3 = Parast | first3 = MM. | title = Pathophysiology of placenta creta: the role of decidua and extravillous trophoblast. | journal = Placenta | volume = 29 | issue = 7 | pages = 639-45 | month = Jul | year = 2008 | doi = 10.1016/j.placenta.2008.04.008 | PMID = 18514815 }}</ref>
*Pathogenesis?
**It is suspected that it arises as there is defect in the endometrium/myometrium -- ''not'' deep trophoblastic invasion.<ref name=pmid18514815/>
 
Note:
*Normal: trophoblastic tissue attaches to the decidua.<ref name=Ref_Pathde_974>{{Ref Pathde|974}}</ref>
 
===Placenta accreta===
*Trophoblastic tissue (directly) adherent to the myometrium.<ref name=Ref_Pathde_974>{{Ref Pathde|974}}</ref>
 
Image:
*[http://library.med.utah.edu/WebPath/jpeg2/PLAC040.jpg Placenta accreta (med.utah.edu)].<ref>URL: [http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/plfrm.html http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/plfrm.html]. Accessed on: 3 December 2011.</ref>
 
===Placenta increta===
*Trophoblastic tissue entends into the myometrium.
 
===Placenta increta===
*Trophoblastic tissue penetrates through the myometrium.


==Placental abruption==
==Placental abruption==
===General===
{{Main|Placental abruption}}
Classic clinical manifestations:<ref name=pmid16752262>{{cite journal |author=Tikkanen M, Nuutila M, Hiilesmaa V, Paavonen J, Ylikorkala O |title=Clinical presentation and risk factors of placental abruption |journal=Acta Obstet Gynecol Scand |volume=85 |issue=6 |pages=700–5 |year=2006 |pmid=16752262 |doi=10.1080/00016340500449915 |url=}}</ref>
*Vaginal bleeding (~70%).
*Abdominal pain (~50%).
*Fetal heart rate abnormalities (~70%).
 
Sign-out:
*Pathologists should sign-out this as "focal adherent retroplacental hematoma".
**The pathologic findings may be due to abruption or manual removal of the placenta.
 
===Gross===
Features:<ref>CS. 7 February 2011.</ref>
*Large adherent blood clot.
*Disc depression on maternal side.
 
Notes:
*Loosely attached clot less convincing.
*Central haemorrhage is the most worrisome.
 
===Microscopic===
Features:
#Decidual hemorrhage.
#*Blood in the decidua.
#Intravillous hemorrhage, [[AKA]] villous stromal hemorrhage.
#*"Bags of blood" - blood outside of vessels in the villi.
#**Should not be confused with congested villi.
 
Notes:
*There are '''no''' definitive microscopic findings for placental abruption.
*Intravillous hemorrhage is non-specific - may arise in the following: early placental infarct, cord compression, abdominal trauma.


=Inflammatory pathologies=
=Inflammatory pathologies=
Line 677: Line 549:


==Membranitis==
==Membranitis==
:''Chorionitis'' redirects here.
===General===  
===General===  
*Controversial. (???)
*Early [[chorioamnionitis]].<ref>{{Cite journal  | last1 = Vedovato | first1 = S. | last2 = Zanardo | first2 = V. | title = [Chorioamnionitis and inflammatory disease in the premature newborn infant]. | journal = Minerva Pediatr | volume = 62 | issue = 3 Suppl 1 | pages = 155-6 | month = Jun | year = 2010 | doi =  | PMID = 21090086 }}</ref>
*Controversial.{{fact}}


===Microscopic===
===Microscopic===
Line 685: Line 559:
*+/-PMNs in subamniotic tissue.
*+/-PMNs in subamniotic tissue.
*+/-Necrosis in decidua or chorion/subamniotic tissue.
*+/-Necrosis in decidua or chorion/subamniotic tissue.
Note:
*Plasma cells in the decidua = [[chronic deciduitis]].
DDx:
*[[Chorioamnionitis]].


====Grading membranitis====
====Grading membranitis====
Line 691: Line 571:
# PMNs - in subamniotic tissue.
# PMNs - in subamniotic tissue.
# 1 or 2 + [[necrosis]] in decidua or chorion/subamniotic tissue.
# 1 or 2 + [[necrosis]] in decidua or chorion/subamniotic tissue.
==Chorioamnionitis==
===General===
*Associated with pre-term labour.<ref name=pmid22958008>{{Cite journal  | last1 = Martinelli | first1 = P. | last2 = Sarno | first2 = L. | last3 = Maruotti | first3 = GM. | last4 = Paludetto | first4 = R. | title = Chorioamnionitis and prematurity: a critical review. | journal = J Matern Fetal Neonatal Med | volume = 25 Suppl 4 | issue =  | pages = 29-31 | month = Oct | year = 2012 | doi = 10.3109/14767058.2012.714981 | PMID = 22958008 }}</ref>
**Classically described as due to an ascending infection.
*At term usually non-infectious.<ref name=pmid22412842>{{Cite journal  | last1 = Roberts | first1 = DJ. | last2 = Celi | first2 = AC. | last3 = Riley | first3 = LE. | last4 = Onderdonk | first4 = AB. | last5 = Boyd | first5 = TK. | last6 = Johnson | first6 = LC. | last7 = Lieberman | first7 = E. | title = Acute histologic chorioamnionitis at term: nearly always noninfectious. | journal = PLoS One | volume = 7 | issue = 3 | pages = e31819 | month =  | year = 2012 | doi = 10.1371/journal.pone.0031819 | PMID = 22412842 }}</ref>
Clinical features:
*Maternal fever.
*Premature rupture of membranes (PROM).
*Non-reassuring fetal heart rate (NRFHR).
===Microscopic===
Features:
*Neutrophils in the amnion.
**Amnion:
***The simple cuboidal epithelium and the paucicellular underlying connective tissue
***Separated from the chorion by an artefactual cleft.
Note:
*Severe cases may have umbilical cord vasculitis or [[funisitis]].
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Chorioamnionitis_-_low_mag.jpg Chorioamnionitis - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Chorioamnionitis_-_high_mag.jpg Chorioamnionitis - high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Chorioamnionitis_-2-_very_high_mag.jpg Chorioamnionitis - very high mag. (WC)].
====Grading chorioamnionitis====
Chorioamnionitis:<ref name=Ref_Sternberg4_2311>{{Ref Sternberg4|2311}}</ref>
# placental chorionic plate only.
# 1 + subamniotic tissue.
# 1 or 2 + necrosis ''or'' abscess.


===Sign out===
===Sign out===
<pre>
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
- CHORIOAMNIONITIS.
- FETAL MEMBRANES WITH CHORIONITIS.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- THREE VESSEL UMBILICAL CORD WITH VASCULITIS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.
- THROMBUS OF THE PLACENTAL DISC (1.3 CM - MAXIMAL DIMENSION).
</pre>
</pre>


==Umbilical cord vasculitis==
====Waffle====
===General===
*Usu. seen together with [[chorioamnionitis]].
 
===Microscopic===
Features:
*Neutrophils in the vessels of the umbilical cord.
 
====Grading====
Umbilical cord vasculitis:<ref name=Ref_Sternberg4_2311>{{Ref Sternberg4|2311}}</ref>
* +0.5 for each vessel.
* +0.5 for each vessel with severe involvement.
 
==Funisitis==
===General===
*Usu. seen together with [[chorioamnionitis]].
 
===Microscopic===
Features:
*Neutrophils in the vessels of the umbilical cord and Wharton's jelly.
 
Note:
*Wharton's jelly = connective tissue of the umbilical cord.
 
====Grading funisitis====
Funisitis:<ref name=Ref_Sternberg4_2311>{{Ref Sternberg4|2311}}</ref>
# Focal inflammation.
# Diffuse inflammation.
# Necrosis - in umbilical vessels or Wharton jelly.
 
===Sign out===
<pre>
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- CHORIOAMNIONITIS.
- FETAL MEMBRANES WITH MECONIUM-LADEN MACROPHAGES AND ABUNDANT DECIDUAL NEUTROPHILS
- THREE VESSEL UMBILICAL CORD WITH FUNISITIS.
  SUSPICIOUS FOR EARLY CHORIONITIS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.
- TWO THROMBI OF THE PLACENTAL DISC (LARGEST 0.9 CM - MAXIMAL DIMENSION).
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
</pre>
</pre>


==Villitis of unknown etiology==
==Chorioamnionitis==
*Abbreviated ''VUE''.
{{Main|Chorioamnionitis}}


===General===
==Umbilical cord vasculitis==
Features:<ref name=pmid17889674>{{cite journal |author=Redline RW |title=Villitis of unknown etiology: noninfectious chronic villitis in the placenta |journal=Hum. Pathol. |volume=38 |issue=10 |pages=1439–46 |year=2007 |month=October |pmid=17889674 |doi=10.1016/j.humpath.2007.05.025 |url=}}</ref>
{{Main|Umbilical cord vasculitis}}
*Usually term placenta.
*Prevalence: 5% to 15% of all placentas.
*Associated with:
**[[Intrauterine growth restriction]] (IUGR).
**Recurrent reproductive loss/adverse outcomes in subsequent pregnancies -- '''key point'''.
***Recurrence in up 37% of cases.<ref name=pmid20604650>{{cite journal |author=Feeley L, Mooney EE |title=Villitis of unknown aetiology: correlation of recurrence with clinical outcome |journal=J Obstet Gynaecol |volume=30 |issue=5 |pages=476–9 |year=2010 |pmid=20604650 |doi=10.3109/01443611003802339 |url=}}</ref>


Etiology:
==Funisitis==
*Unknown - as the name of the entity suggests.
{{Main|Funisitis}}
**Suspected to be immune-mediated.
*Inflammation of Wharton's jelly - the connective tissue of the umbilical cord.


===Microscopic===
==Acute villitis==
Features:<ref name=pmid17889674/>
{{main|Acute villitis}}
*Lymphocytes in villous stroma - '''key feature'''.
**Usually focal/patchy.
**Lymphocytes: maternal derivation, T-lymphocytes -- mostly CD8-positive.
*+/-Intervillositis (lymphocytes between villi).
*+/-Histiocytes.


Notes:
==Villitis of unknown etiology==
*Lymphocytes are smaller and stain darker than the cells of the villi. (???)
{{Main|Villitis of unknown etiology}}
*Neutrophils are usually absent.  A significant number of 'em is suggestive of an infectious villitis.
*Infective villitis is usu. B-cell predominant.
*'''No''' plasma cells - this suggests an infectious etiology.<ref>CS. 7 February 2011.</ref>
**Plasma cells may be seen in the decidua -- these can be ignored.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Villitis_of_unknown_etiology_-_intermed_mag.jpg VUE - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Villitis_of_unknown_etiology_-_very_high_mag.jpg VUE - very high mag. (WC)].
*www:
**[http://jcp.bmj.com/content/61/12/1254/F6.large.jpg VUE (bmj.com)].<ref>URL: [http://jcp.bmj.com/content/61/12/1254.abstract http://jcp.bmj.com/content/61/12/1254.abstract]. Accessed on: 11 January 2011.</ref>
**[http://farm4.static.flickr.com/3501/3954021698_84a3542b43.jpg VUE (flickr.com)].<ref name=jian>URL: [http://www.flickr.com/photos/jian-hua_qiao_md/3954021698/ http://www.flickr.com/photos/jian-hua_qiao_md/3954021698/]. Accessed on: 11 January 2011.</ref>
**[http://www.flickr.com/photos/jian-hua_qiao_md/3954022678/in/photostream/ VUE (flickr.com)].<ref name=jian>URL: [http://www.flickr.com/photos/jian-hua_qiao_md/3954021698/ http://www.flickr.com/photos/jian-hua_qiao_md/3954021698/]. Accessed on: 11 January 2011.</ref>


==Intervillitis==
==Chronic intervillitis==
*[[AKA]] ''intervillositis''. (???)
*[[AKA]] ''chronic intervillositis''.<ref name=pmid8215826>{{Cite journal  | last1 = Jacques | first1 = SM. | last2 = Qureshi | first2 = F. | title = Chronic intervillositis of the placenta. | journal = Arch Pathol Lab Med | volume = 117 | issue = 10 | pages = 1032-5 | month = Oct | year = 1993 | doi =  | PMID = 8215826 }}</ref>


===General===
===General===
Line 821: Line 613:
*Recurs.
*Recurs.
===Microscopic===
===Microscopic===
Features:<ref name=pmid17088773/>
Features:<ref name=pmid8215826/><ref name=pmid17088773/>
*Intervillous inflammatory cells:
*Intervillous inflammatory cells:
**Lymphocytes.
**Lymphocytes.
Line 827: Line 619:
*Fibrinoid deposition.
*Fibrinoid deposition.


Images:
====Images====
*[http://commons.wikimedia.org/wiki/File:Intervillitis_-_intermed_mag.jpg Intervillitis - intermed. mag. (WC)].
<gallery>
*[http://commons.wikimedia.org/wiki/File:Intervillitis_-_very_high_mag.jpg Intervillitis - very high mag. (WC)].
Image:Intervillitis_-_intermed_mag.jpg | Intervillitis - intermed. mag. (WC)
 
Image:Intervillitis_-_very_high_mag.jpg | Intervillitis - very high mag. (WC)
</gallery>
==Chronic deciduitis==
==Chronic deciduitis==
*[[AKA]] plasma cell deciduitis.
*[[AKA]] plasma cell deciduitis.
 
{{Main|Chronic deciduitis}}
===General===
*Associated with preterm labour.<ref name=pmid18171100>{{Cite journal  | last1 = Edmondson | first1 = N. | last2 = Bocking | first2 = A. | last3 = Machin | first3 = G. | last4 = Rizek | first4 = R. | last5 = Watson | first5 = C. | last6 = Keating | first6 = S. | title = The prevalence of chronic deciduitis in cases of preterm labor without clinical chorioamnionitis. | journal = Pediatr Dev Pathol | volume = 12 | issue = 1 | pages = 16-21 | month =  | year =  | doi = 10.2350/07-04-0270.1 | PMID = 18171100 }}</ref>
 
===Microscopic===
Features:<ref name=pmid18171100/>
*Plasma cells within the decidua.
 
Notes:
*Decidua = maternal tissue.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Chronic_deciduitis_-_intermed_mag.jpg Chronic deciduitis - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Chronic_deciduitis_-_very_high_mag.jpg Chronic deciduitis - very high mag. (WC)].


=Placental infarction=
=Placental infarction=
==True infarcts==
==True infarcts==
{{Main|Infarction}}
{{Main|Placental infarct}}
===General===
*May be seen in conjunction with a retroplacental hematoma.
*Infarcts frequently associated with [[hypertension]].<ref>URL: [http://www.medind.nic.in/jae/t04/i1/jaet04i1p27.pdf http://www.medind.nic.in/jae/t04/i1/jaet04i1p27.pdf]. Accessed on: 16 April 2012.</ref><ref name=pmid11969346>{{Cite journal  | last1 = Becroft | first1 = DM. | last2 = Thompson | first2 = JM. | last3 = Mitchell | first3 = EA. | title = The epidemiology of placental infarction at term. | journal = Placenta | volume = 23 | issue = 4 | pages = 343-51 | month = Apr | year = 2002 | doi = 10.1053/plac.2001.0777 | PMID = 11969346 }}</ref>
 
Note: "[[Maternal floor infarct]]" is ''not'' a true infarct.<ref name=Ref_TPoSP178>{{Ref TPoSP|178}}</ref>
 
===Gross===
Features:<ref name=Ref_WMSP465>{{Ref WMSP|465}}</ref>
*Early - red.
*Late - white/grey.
 
====Significant infarcts====
*> 3cm --or-- central location --or-- in 1st or 2nd trimester.{{fact}}
**Small foci are accepted in term placentae - typically at periphery.
 
Images:
*[http://pathweb.uchc.edu/eatlas/gyn/681b.htm Placental infarcts (pathweb.uchc.edu)].
*[http://library.med.utah.edu/WebPath/PLACHTML/PLAC044.html Placental infarcts (med.utah.edu)].
 
===Microscopic===
Features:
#Necrosis of villi; hyaline material (acellular eosinophilic material) replaces the stroma of the villi.
#Loss of intervillous space.<ref name=Ref_WMSP465>{{Ref WMSP|465}}</ref>
#*Villi appear to be crowded.<ref>{{Ref PBoD|1109}}</ref>
#**Normal spacing is ~1x smallest villus or larger.
#***In perivillous fibrin deposition - spacing usu. larger than normal.
#Prominent syncytial knots.
#Thickened trophoblastic basement membrane (below [[cytotrophoblast]]s).
#+/-Changes seen in decidual vasculopathy:
#*Acute atherosis (vaguely like [[atherosclerosis]]).
#**[[Fibrinoid necrosis]].
#**Vessel wall lipid deposition.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Placental_infarct_-_low_mag.jpg Placental infarct - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Placental_infarct_-_intermed_mag.jpg Placental infarct - intermed. mag. (WC)].
*www:
**[http://pathweb.uchc.edu/eatlas/gyn/1203b.htm Recent infarct (pathweb.uchc.edu)].
**[http://path.upmc.edu/cases/case75/images/micro1.jpg Placental infarct (umpmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case75/micro.html http://path.upmc.edu/cases/case75/micro.html]. Accessed on: 6 January 2011.</ref>
**[http://www.mda-sy.com/pathology/PLACHTML/PLAC024.HTM Placental infarct - necrotic villi (mda-sy.com)].


==Perivillous fibrin deposition==
==Perivillous fibrin deposition==
*Abbreviation ''PFD''.
*Abbreviation ''PFD''.
===General===
===General===
*Massive perivillous fibrin deposition is assoc. with anti-phospholipid antibody (APLA) syndrome.<ref name=pmid12066949>{{cite journal |author=Sebire NJ, Backos M, Goldin RD, Regan L |title=Placental massive perivillous fibrin deposition associated with antiphospholipid antibody syndrome |journal=BJOG |volume=109 |issue=5 |pages=570–3 |year=2002 |month=May |pmid=12066949 |doi= |url=http://www3.interscience.wiley.com/resolve/openurl?genre=article&sid=nlm:pubmed&issn=1470-0328&date=2002&volume=109&issue=5&spage=570}}</ref>
*Thought to be an immunologic problem - resulting in platelet activation and fibrin deposition.<ref name=pmid12066949>{{Cite journal | last1 = Sebire | first1 = NJ. | last2 = Backos | first2 = M. | last3 = Goldin | first3 = RD. | last4 = Regan | first4 = L. | title = Placental massive perivillous fibrin deposition associated with antiphospholipid antibody syndrome. | journal = BJOG | volume = 109 | issue = 5 | pages = 570-3 | month = May | year = 2002 | doi = | PMID = 12066949 }}</ref>
**APLA is assoc. with recurrent miscarriage - can be treated with heparin + ASA.<ref name=pmid12066949/>
*Thought to be an immunologic problem - resulting in platelet activation and fibrin deposition.<ref name=pmid12066949/>
*May be associated with [[diabetes mellitus]].<ref name=Ref_Placenta327>{{Ref Placenta|327}}</ref>
*May be associated with [[diabetes mellitus]].<ref name=Ref_Placenta327>{{Ref Placenta|327}}</ref>


Line 913: Line 650:


Notes:
Notes:
*Nuclei of villi are usu. preserved.
*Nuclei of villi are usually preserved.
*Villi may have secondary infarction, i.e. there may be [[Basics#Nuclear destruction words|nuclear destruction]] (karyolysis, karyorrhexis, pyknosis).
*Villi may have secondary infarction, i.e. there may be [[Basics#Nuclear destruction words|nuclear destruction]] (karyolysis, karyorrhexis, pyknosis).
DDx:
*[[Placental infarction]] - loss of nuclei in the villi (below the edge of the lesion).
*[[Massive perivillous fibrin deposition]] (maternal floor infarct).


Images:
Images:
Line 929: Line 670:
</pre>
</pre>


==Maternal floor infarct==
==Maternal floor infarction==
*Abbreviated ''MFI''.
*Formally ''placental maternal floor infarction''.
*Formally ''placental maternal floor infarction''.
===General===
*[[AKA]] ''massive perivillous fibrin deposition''.<ref name=Ref_Placenta367>{{Ref Placenta|367}}</ref>
*'''''Not''''' a true infact.
{{Main|Maternal floor infarction}}
**It is really fibrin deposition.<ref name=Ref_TPoSP178>{{Ref TPoSP|178}}</ref>
*Associated with [[intrauterine growth restriction]] (IUGR).<ref name=pmid18641412>{{Cite journal  | last1 = Roberts | first1 = DJ. | last2 = Post | first2 = MD. | title = The placenta in pre-eclampsia and intrauterine growth restriction. | journal = J Clin Pathol | volume = 61 | issue = 12 | pages = 1254-60 | month = Dec | year = 2008 | doi = 10.1136/jcp.2008.055236 | PMID = 18641412 }}</ref>
===Microscopic===
Features:
*Fibrin deposition around villi on maternal aspect - see: ''[[Perivillous fibrin deposition]]''.
 
Images:
*[http://www.flickr.com/photos/jian-hua_qiao_md/3987724630/ Maternal floor infarct (flickr.com)].
*[http://www.flickr.com/photos/jian-hua_qiao_md/3986970923/ Maternal floor infarct (flickr.com)].
*[http://path.upmc.edu/cases/case224.html Maternal floor infarct - several images (upmc.edu)].


=Fetal disease=
=Fetal disease=
Line 952: Line 684:
**''Fetal artery stem thrombosis''.
**''Fetal artery stem thrombosis''.
*The multitude of terms reflects the confusion about this finding and that it has numerous etiologies.<ref name=pmid19237859/>
*The multitude of terms reflects the confusion about this finding and that it has numerous etiologies.<ref name=pmid19237859/>
===General===
{{Main|Fetal thrombotic vasculopathy}}
*May cause [[IUGR]].
*Associated with cerebral palsy and common in perinatal deaths.<ref name=pmid10414494>{{cite journal |author=Kraus FT, Acheen VI |title=Fetal thrombotic vasculopathy in the placenta: cerebral thrombi and infarcts, coagulopathies, and cerebral palsy |journal=Hum. Pathol. |volume=30 |issue=7 |pages=759–69 |year=1999 |month=July |pmid=10414494 |doi= |url=}}</ref>
 
===Microscopic===
Features:<ref name=pmid10414494>{{Cite journal  | last1 = Kraus | first1 = FT. | last2 = Acheen | first2 = VI. | title = Fetal thrombotic vasculopathy in the placenta: cerebral thrombi and infarcts, coagulopathies, and cerebral palsy. | journal = Hum Pathol | volume = 30 | issue = 7 | pages = 759-69 | month = Jul | year = 1999 | doi =  | PMID = 10414494 }}</ref>
*Thrombus in the fetal vasculature +/- recanalization.
**Eosinophilic (light pink on H&E), moderately granular intravascular material (fibrin) with layering.
*Clustered fibrotic villi without blood vessels - '''key feature'''.
**This is a chronic change.
 
Images:
*www:
**[http://jcp.bmj.com/content/61/12/1254/F8.large.jpg FTV (bmj.com)].<ref>URL: [http://jcp.bmj.com/content/61/12/1254.abstract http://jcp.bmj.com/content/61/12/1254.abstract]. Accessed on: 12 January 2011.</ref>
**[http://gut.bmj.com/content/41/3/354/F3.large.jpg Thrombus - rat (bmj.com)].<ref>URL: [http://gut.bmj.com/content/41/3/354.full http://gut.bmj.com/content/41/3/354.full]. Accessed on: 12 January 2011.</ref>
**[http://www.womenandinfants.org/fertilityandpregnancy/images/FTV.Fig.4a.jpg FTV - low mag. (womenandinfants.org)].<ref>URL: [http://www.womenandinfants.org/fertilityandpregnancy/current-topics-in-perinatal-pathology.cfm http://www.womenandinfants.org/fertilityandpregnancy/current-topics-in-perinatal-pathology.cfm]. Accessed on: 17 December 2012.</ref>
**[http://www.womenandinfants.org/fertilityandpregnancy/images/FTV.Fig.4b.jpg FTV - high mag. (womenandinfants.org)].
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Fetal_thrombotic_vasculopathy_-_intermed_mag.jpg FTV - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Fetal_thrombotic_vasculopathy_-_high_mag.jpg FTV - high mag. (WC)].


==Hemorrhagic endovasculitis==
==Hemorrhagic endovasculitis==
Line 1,000: Line 713:


Notes:
Notes:
*One should look for the changes in the membrane roll, not the maternal surface.<ref>CS. 7 February 2011.</ref>
*One should look for the changes in the membrane roll, not the maternal surface.<ref>Sherman, C. 7 February 2011.</ref>
 
Images:
*[http://www.pathxchange.org/case/19711 Pregnancy-induced hypertension (pathxchange.org)].


==Hypertrophic decidual vasculopathy==
==Hypertrophic decidual vasculopathy==
===General===
:[[AKA]] ''decidual vasculopathy''.
*A change seen in hypertension.
{{Main|Hypertrophic decidual vasculopathy}}
*Seen in [[intrauterine growth restriction]] (IUGR).
 
===Microscopic===
Features:<ref name=pmid18641412>{{Cite journal  | last1 = Roberts | first1 = DJ. | last2 = Post | first2 = MD. | title = The placenta in pre-eclampsia and intrauterine growth restriction. | journal = J Clin Pathol | volume = 61 | issue = 12 | pages = 1254-60 | month = Dec | year = 2008 | doi = 10.1136/jcp.2008.055236 | PMID = 18641412 }}</ref>
*Mild or moderate:
*#Perivascular inflammatory cells.
*#+/-Vascular [[thrombosis]].
*#Smooth muscle hypertrophy.
*#Endothelial hyperplasia.
*#*Above two lead to narrowing of the decidual spiral arteries<ref>AFIP - Placental Pathology. P.122. ISBN: 1-881041-89-1. 2004.</ref> -- '''key feature'''.
*Severe:<ref name=pmid18641412/>
*#Atherosis of maternal blood vessels.
*#*Foamy macrophages within vascular wall.
*#[[Fibrinoid necrosis]] of vessel wall (amorphous eosinophilic material vessel wall).
 
Note:
*''Smooth muscle hypertrophy'' can also be understood as ''lack of physiological conversion of spiral arteries of the uterus''.<ref name=pmid12848643>{{Cite journal  | last1 = Naicker | first1 = T. | last2 = Khedun | first2 = SM. | last3 = Moodley | first3 = J. | last4 = Pijnenborg | first4 = R. | title = Quantitative analysis of trophoblast invasion in preeclampsia. | journal = Acta Obstet Gynecol Scand | volume = 82 | issue = 8 | pages = 722-9 | month = Aug | year = 2003 | doi =  | PMID = 12848643 }}</ref>
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Hypertrophic_decidual_vasculopathy_intermed_mag.jpg HDV - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Hypertrophic_decidual_vasculopathy_low_mag.jpg HDV - low mag. (WC)].
*www:
**[http://path.upmc.edu/cases/case75/images/micro2.jpg Atherosis (upmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case75.html http://path.upmc.edu/cases/case75.html]. Accessed on: 2 January 2012.</ref>


==HELLP syndrome==
==HELLP syndrome==
===General===
{{Main|HELLP syndrome}}
*Diagnosed clinically.
*Pathologically not the same as ''severe preclampsia''.<ref name=pmid18362224>{{cite journal |author=Vinnars MT, Wijnaendts LC, Westgren M, Bolte AC, Papadogiannakis N, Nasiell J |title=Severe preeclampsia with and without HELLP differ with regard to placental pathology |journal=Hypertension |volume=51 |issue=5 |pages=1295–9 |year=2008 |month=May |pmid=18362224 |doi=10.1161/HYPERTENSIONAHA.107.104844 |url=}}</ref>
 
Definition:
*'''H''' = hemolysis.
*'''EL''' = elevated liver enzymes.
*'''LP''' = low platelets.
 
===Microscopic===
Features:<ref name=pmid7966086>{{cite journal |author=Ornstein MH, Rand JH |title=An association between refractory HELLP syndrome and antiphospholipid antibodies during pregnancy; a report of 2 cases |journal=J. Rheumatol. |volume=21 |issue=7 |pages=1360–4 |year=1994 |month=July |pmid=7966086 |doi= |url=}}</ref>
*Thrombotic microangiopathic vasculopathy.
**In essence: severe ''hypertrophic decidual vasculopathy''. (???)


==Malaria==
==Malaria==
Line 1,055: Line 735:
*[[RBC]]s with basophilic dots ~1-2 micrometres.
*[[RBC]]s with basophilic dots ~1-2 micrometres.


Image:
====Image====
*[http://commons.wikimedia.org/wiki/File:Maternal_malaria_placenta_-_very_high_mag.jpg Maternal malaria - very high mag. (WC)].
<gallery>
 
Image:Maternal_malaria_placenta_-_very_high_mag.jpg | Maternal malaria - very high mag. (WC)
</gallery>
=Tumours=
=Tumours=
{{main|Gestational trophoblastic disease}}
{{main|Gestational trophoblastic disease}}


==Chorangioma==
==Chorangioma==
===General===
{{Main|Chorangioma}}
*[[Hamartoma]]-like growth in the placenta consisting of [[blood vessel]]s.<ref name=pmid20594143>{{cite journal |author=Amer HZ, Heller DS |title=Chorangioma and related vascular lesions of the placenta--a review |journal=Fetal Pediatr Pathol |volume=29 |issue=4 |pages=199–206 |year=2010 |pmid=20594143 |doi=10.3109/15513815.2010.487009 |url=}}</ref>
 
Epidemiology:
*Often benign/insignificant; large lesions (>4 cm<ref name=pmid20594143>{{cite journal |author=Amer HZ, Heller DS |title=Chorangioma and related vascular lesions of the placenta--a review |journal=Fetal Pediatr Pathol |volume=29 |issue=4 |pages=199–206 |year=2010 |pmid=20594143 |doi=10.3109/15513815.2010.487009 |url=}}</ref> or >5 cm<ref name=pmid21234259>{{cite journal |author=Lež C, Fures R, Hrgovic Z, Belina S, Fajdic J, Münstedt K |title=Chorangioma placentae |journal=Rare Tumors |volume=2 |issue=4 |pages=e67 |year=2010 |pmid=21234259 |pmc=3019602 |doi=10.4081/rt.2010.e67 |url=}}</ref>) or multiple lesions are significant.
*May be association with:
**Fetal maternal haemorrhage.
**[[Fetal hydrops]].
**[[IUGR]].
*Incidence: ~1 in 100 placentas.<ref name=pmid20594143/>
 
===Gross===
*White lesions.
**Occasionally red lesions.
 
===Microscopic===
Features:<ref name=pmid20594143/>
*Mass of capillaries - '''key feature'''.
*+/-High cellularity.
*+/-Degenerative changes.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Chorangioma_-_intermed_mag.jpg Chorangioma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Chorangioma_-_low_mag.jpg Chorangioma - low mag. (WC)].
 
Notes:
*Must be differentiated from [[chorangiomatosis]] (associated with preeclampsia & IUGR) and chorangiosis (assoc. with maternal [[diabetes mellitus]]).<ref name=pmid20594143/>


==Chorangiomatosis==
==Chorangiomatosis==
Line 1,107: Line 762:


==Chorangiosis==
==Chorangiosis==
===General===
{{Main|Chorangiosis}}
*Should not be confused with [[chorangioma]].
*Relative common among babies in ICU ~5%.<ref>URL: [http://www.bhj.org/journal/2009_5102_april/download/pg251-252.pdf http://www.bhj.org/journal/2009_5102_april/download/pg251-252.pdf]. Accessed on: 26 July 2011.</ref>
 
Associations:
*Maternal hypoxia:
**[[Smoking]].
**Altitude.
**Gestational [[diabetes]].<ref name=pmid18382864>{{Cite journal  | last1 = Daskalakis | first1 = G. | last2 = Marinopoulos | first2 = S. | last3 = Krielesi | first3 = V. | last4 = Papapanagiotou | first4 = A. | last5 = Papantoniou | first5 = N. | last6 = Mesogitis | first6 = S. | last7 = Antsaklis | first7 = A. | title = Placental pathology in women with gestational diabetes. | journal = Acta Obstet Gynecol Scand | volume = 87 | issue = 4 | pages = 403-7 | month =  | year = 2008 | doi = 10.1080/00016340801908783 | PMID = 18382864 }}</ref>
 
===Gross===
*Usually not seen on gross pathology.
 
===Microscopic===
Features:
*Increased blood vessels in the terminal villi.
**Altshuler criteria: "a minimum of 10 villi, each with 10 or more vascular channels, in 3 or more random, non-infarcted placental areas when using a ×10 ocular."<ref name=pmid6546343>{{Cite journal  | last1 = Altshuler | first1 = G. | title = Chorangiosis. An important placental sign of neonatal morbidity and mortality. | journal = Arch Pathol Lab Med | volume = 108 | issue = 1 | pages = 71-4 | month = Jan | year = 1984 | doi =  | PMID = 6546343 }}</ref><ref name=pmid11520290/><ref>URL: [http://path.upmc.edu/cases/case655/dx.html http://path.upmc.edu/cases/case655/dx.html]. Accessed on: 28 January 2012.</ref>
***The definition suffers from [[IPFitis]].
*Lesion ''not'' well circumscribed.
*Villi tend to be larger and have centrally placed blood vessels.<ref>E. Latta. 26 July 2011.</ref>
 
Notes:
*Normal villi have up to five vascular channels.<ref name=pmid11520290>{{Cite journal  | last1 = De La Ossa | first1 = MM. | last2 = Cabello-Inchausti | first2 = B. | last3 = Robinson | first3 = MJ. | title = Placental chorangiosis. | journal = Arch Pathol Lab Med | volume = 125 | issue = 9 | pages = 1258 | month = Sep | year = 2001 | doi = 10.1043/0003-9985(2001)1251258:PC2.0.CO;2 | PMID = 11520290 | url=http://www.archivesofpathology.org/doi/full/10.1043/0003-9985%282001%29125%3C1258:PC%3E2.0.CO;2}}</ref>
 
Images:
*[http://commons.wikimedia.org/wiki/File:Chorangiosis_-_intermed_mag.jpg Chorangiosis - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Chorangiosis_-_high_mag.jpg Chorangiosis - high mag. (WC)].
 
===Sign out===
<pre>
PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN MECONIUM STAINING OF THE AMNION, NEGATIVE FOR CHORIOAMNIONITIS.
- PLACENTAL DISC WITH:
-- CHORANGIOSIS.
-- FOCAL PERIVILLOUS FIBRIN DEPOSITION.
 
COMMENT:
Chorangiosis is a non-specific finding that may be associated with diabetes, smoking or high altitude.
</pre>


=Other=
=Other=
Line 1,152: Line 768:
*May be spelled ''foetus papyraceus''.
*May be spelled ''foetus papyraceus''.
*[[AKA]] ''fetus compressus''.
*[[AKA]] ''fetus compressus''.
{{Main|Fetus papyraceus}}


===General===
==Placental mesenchymal dysplasia==
*Remnant of a dead fetus usu. from a twin pregnancy.
*Abbreviated ''PMD''.
**No clinical consequence for mother and remaining fetus.
{{Main|Placental mesenchymal dysplasia}}


Clinical:<ref name=Ref_Placenta141>{{Ref Placenta|141}}</ref>
=Placental cysts and pseudocysts=
*Documented multiple gestation by imaging.
Types:<ref name=Ref_Placenta219-220>{{Ref Placenta|219-220}}</ref>
*Elevated AFP.
*Amnionic epithelial inclusion cyst (amniotic cyst).
*May be a "fetal reduction" in the context of ''in vitro'' fertilization (IVF).
*[[Epidermal inclusion cyst]] - lined by keratinized squamous epithelium.
*Chorionic cyst ([[AKA]] chorionic pseudocyts).
*Cell island cyst.


Note:
Other considerations:<ref name=pmid12054300>{{Cite journal  | last1 = Brown | first1 = DL. | last2 = DiSalvo | first2 = DN. | last3 = Frates | first3 = MC. | last4 = Davidson | first4 = KM. | last5 = Genest | first5 = DR. | title = Placental surface cysts detected on sonography: histologic and clinical correlation. | journal = J Ultrasound Med | volume = 21 | issue = 6 | pages = 641-6; quiz 647-8 | month = Jun | year = 2002 | doi =  | PMID = 12054300 }}</ref>
*"Papyraceus" = paper-like.
*Hematoma.
*Fibrin-lined pseudocyst.


===Gross===
General:<ref name=pmid12054300/>
*Pale yellow flattened disk or plaque with a pigmented macule<ref name=Ref_Placenta141>{{Ref Placenta|141}}</ref> - on membranes or placental disc.
*Usually good outcome.
 
*Large cysts (>4.5 cm) or multiple cysts (>3) are associated with [[IUGR]].
===Microscopic===
Features:
*Fetal structures - such as:
**Cartilage.
**Bone.


Images:
Images:
*[http://www.nejm.org/doi/full/10.1056/NEJMicm020196 Fetus papyraceus (nejm.org)].
*[http://www.jultrasoundmed.org/content/21/6/641/F5.expansion.html Subchorionic cysts (jultrasoundmed.org)].<ref name=pmid12054300/>
*[http://path.upmc.edu/cases/case128.html Fetus papyraceus (upmc.edu)].
*[http://www.neonet.ch/en/03_Case_of_the_month/archive/11_dermatologic_disorders/2002_10.asp Fetus papyraceus (neonet.ch)].<ref>URL: [http://www.neonet.ch/en/03_Case_of_the_month/archive/11_dermatologic_disorders/2002_10.asp http://www.neonet.ch/en/03_Case_of_the_month/archive/11_dermatologic_disorders/2002_10.asp]. Accessed on: 3 January 2012.</ref>


=See also=
=See also=
Line 1,195: Line 808:
=External links=
=External links=
*[http://emedicine.medscape.com/article/262470-overview Cord complications (emedicine.medscape.com)].
*[http://emedicine.medscape.com/article/262470-overview Cord complications (emedicine.medscape.com)].
*[http://www.palpath.com/MedicalTestPages/placenta2.htm Placenta notes (palpath.com)].


[[Category:Placenta]]
[[Category:Placenta]]

Latest revision as of 15:27, 10 May 2018

The placenta feeds the developing baby, breathes for it and disposes of its waste.

A placenta (fetal aspect) with attached umbilical cord. (WC/Asturnut)

The organ is one that seems to be left behind; at least one review suggests it isn't done so well by general pathologists.[1]

Placental pathology redirects to this article.

Clinical

Examination of the placenta

  • Most placentas are not examined by a pathologist.

Indications for exam by pathology

Some indications for exam by a pathologist:

  • Abnormalities in the:
    1. Fetus:
      • Bad fetal outcome.
      • Suspected or known congenital abnormalities or chromosomal abnormalities.
      • IUGR.
    2. Mother:
      • Infection/suspected infection.
      • Pre-term labour.
      • Maternal disease (e.g. SLE, coagulopathy).
      • Complicated pregnancy (preclampsia, pregnancy induced hypertension, gestational diabetes).
    3. Placenta:
      • Unusual gross characteristics.[2]

A more detailed list is given by Hargitai et al.[3] and Chang.[4]

Most common

Most common reasons for submitting a placenta to pathology:[5]

  1. Prematurity.
  2. PROM / possible chorioamnionitis.
  3. Multiple gestation.

Bleeding in late pregnancy

DDx of bleeding in late pregnancy:

Clinical screening tests

Main article: Pregnancy
  • PAPP-A - low values seen in aneuploidy.[6]

Abbreviations

  • C/S = Caesarean section.
  • LSCS = lower segment C-section.
  • FTP = failure to progress.
  • PROM = premature rupture of membranes.
  • PPROM = preterm premature ruptures of membranes.
  • IUGR = intrauterine growth restriction.
  • IOL = induction of labour.

Normal histology

Villi

Main article: Chorionic villi

This is dealt with in a separate article that also covers the types of trophoblast (cytotrophoblast, syncytiotrophoblast, intermediate trophoblast).

Cord

Omphalomesenteric duct remnant

  • AKA vitelline duct.
  • Benign embryologic remnant.

Features:

  • Duct with benign looking cuboidal epithelium.

Allantoic duct remnant

  • Benign embryologic remnant.

Features:

  • Duct with benign looking flat epithelium.

Vitelline artery remnant

Features:

  • Small artery in the cord.

Membranes

Fetus to mother:

  • Amnion - thin layer: one cell layer, basement membrane, connective tissue.
  • Cleft - artifactual - empty space.
  • Chorion - vascular.
  • Decidua (maternal tissue) - may contain obsolete chorionic villi; place to look for hypertensive changes.

Amnion

General:

  • Next to fetus, surrounds amniotic fluid, avascular.

Characteristics:

  • Characterized by a single layer of cells.[7]
    • Cuboidal/squamoid shape.
    • Eosinophilic cytoplasm.
    • Central nucleus.
  • Squamous metaplasia may be seen at cord insertion.
  • Basement membrane.
  • 'Compact layer'.[7]
  • 'Fibroblastic layer'.[7]

Chorion

General:

  • Surrounds amnion.

Characteristics:

  • Layers:[8]
    • 'Reticular layer' - cellular (inner aspect).
    • 'Pseudo-basemement membrane'.
    • 'Outer trophoblastic layer'.
  • Has blood vessels.
  • Opposed to "trophoblastic X cells" on side opposite of amnion.[7]
    • Beneath of the "trophoblastic X cells" is decidua (mnemonic NEW = nucleus central, eosinophilic, well-defined cell border), which is maternal tissue.

Note:

  • Fibrin deposition may be found deep to the chorion - known as subchorionic fibrin deposition.
    • Gross: subchorionic, white/yellow, laminated, classically has a triangular-shape with the base of triangle parallel to fetal aspect of disc.
      • Arises due to localized stasis of the inter-villous maternal blood.
    • Focal small deposits are considered to be a normal finding - seen in ~15% of cases.[9][10]

Image:

Common terms

  • Chorionic plate - fetal aspect of placenta.
  • Basal plate - maternal aspect of placenta.
    • Has extravillous trophoblast.
    • Place to look for maternal vessels.

Grossing

This is often very quick. The gross is quite important, as some things cannot be diagnosed microscopically.

General

  • Dimensions:
    • Disc.
    • Length of cord, diameter of cord.
    • Accessory lobes - dimensions.
      • Two lobes of equal size + cord arises in between = bilobate placenta.
  • Mass (weight).
    • Should be done 'trimmed' (cord cut-off, membrane cut-off).
    • Should be done when placenta is "fresh", i.e. not fixed -- as mass tables are based on fresh state.
  • Umbilical cord
    • Attachment.
      • Location: central, eccentric, marginal.
        • Marginal attachment assoc. with hypertension[11]
      • Membranous or velamentous (veil-like) insertion.
        • Vessels separate/branch prior to reaching placental disc.
      • Furcate insertion - blood vessels separate before reaching placenta disc/not surrounded by Wharton's jelly - vessels more exposed to trauma (risk for vasa previa).
    • Knots (false vs. true).
      • False knots are nothing to worry about -- look like a knot but aren't really one.
    • Twisting/coiling - 1-3 coils/10 cm is normal.
    • Number of vessels.
      • Normal: 2 arteries, 1 vein.
  • Membranes - shiny & translucent - normal (green, opaque/dull - chorioamnionitis).
    • Attachment (insertion): marginal (normal), circummarginate (inside edge), circumvallate (folding on self).
    • Site of rupture - if obvious; low point of rupture suggests low-lying placenta.
  • Placental disc.
    • Fetal surface - normal is shinny.
      • Dull in chorioamnionitis.
    • Maternal surface
      • Are the cotyledons intact?
      • Adherent clot?
    • Parenchyma - after sectioning:
      • White vs. red nodules.

Notes:

Sections

  1. Cord two sections.
  2. Membranes (rolled), two rolls or more.[12]
  3. Cord at insertion + disc.
  4. Placenta - full thickness (maternal and fetal surface).
    • Sections should not be taken at the margin of the disc.

Placental membranes

Appearance:[13]

Placental mass

It is considered routine to obtain a mass for the placenta. This is usually done when the placenta is fresh and with the membranes and cord trimmed, as most tables of placental mass were created with these parameters.

Placental mass by gestational age:[15]

Gest. Age/Percentile 25% 50% 75%
32 weeks 275 g 318 g 377 g
36 weeks 369 g 440 g 508 g
40 weeks 440 g 501 g 572 g

Linear regression - placental mass-gestational age

Based on the table in the AFIP book[16] one can generate the following regression lines:

50% 10% 90%
slope (g/week) 21.58088235 19.70588235 25.40196078
y-intercept (g) -357.4558824 -397.2352941 -366.7254902
Pearson (r) 0.988670724 0.988268672 0.982206408

placental mass = slope x gestational age + intercept

What to remember...

Extrapolated from the linear regression (see above):

  • 50% at term = 500 grams.
  • 50% at 26 weeks = 200 grams.
  • The change in mass/week is approximately linear and equal to 300 grams / 14 weeks ~ 20 grams/week.
  • The spread in mass between 10% and 90%, crudely estimated, is 200 grams (for GA=26-40).

Notes:

  • Is it required?
    • Sebire and Fox have advocated abandoning the practise of obtaining a placental mass, due to the large number of uncontrolled variables inherent in these measures. Instead, they have advocated using mushy descriptors such as "small", "average" and "large", which require experience in examining the organ.[17]
      • In the context of quality, a measure (even if somewhat flawed) is probably more reproducible and objective than arbitrary descriptors which require experience and a continuing case volume to calibrate.

Placentomegaly

  • AKA large placenta.

Associations:[18]

Lame causes of a heavy placenta:

  • Dates wrong - error in determining the estimated date of confinement.
  • Adherent blood clot.

Comment:

  • Most of causes seem to have one thing in common:
    • There is a decreased oxygen delivery to the fetus.

Sign out

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
- LARGE PLACENTA (819 GRAMS -- TRIMMED, POST-FIXATION WEIGHT).
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.

Placental growth restriction

  • AKA placenta small for gestational age.
  • Small placenta redirects here.

Associations:

  • Maternal vascular disease, e.g. hypertension.
  • Fetal malformations.

Sign out

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- PLACENTA SMALL FOR GESTATIONAL AGE (160 GRAMS -- TRIMMED, POST-FIXATION WEIGHT).
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITH:
-- OLD CENTRAL TRANSMURAL INFARCT (1.7 CM MAXIMAL DIMENSION).

COMMENT:
The 10th percentile placental mass (pre-fixation) for 34 weeks and 2 days is approximately 390 grams.

Overview of placental pathology

Approach

The pathology of the placenta is diverse and is not easy to group.

It terms of remembering things. It is probably easiest to take a combined anatomical, etiologic and morphologic approach.

Anatomical basis:

  • Cord.
  • Membranes.
  • Disc.

Etiologic:

  • Congential.
  • Infectious.
  • Neoplastic.
  • Endocrine.
  • Trauma.
  • Vascular.
  • Degenerative.
  • Autoimmune.
  • Toxic.
  • Idiopathic.

Compartmental:

  • Vasculature.
  • Membranes.
  • Parenchyma:
    • Maternal part (decidua).
    • Fetal part (villi, cord).

Common entities/diagnoses

Sign out

What should be commented on...

  • Placenta:
    • Maturity of villi (2nd or 3rd trimester).
    • Infarction?
      • Subchorionic less important than maternal aspect.
      • Peripheral aspect of placental disc less important than central region of disc.
    • Blood vessels.
      • Maternal.
      • Fetal.
  • Membranes.
  • Cord:
    • 3 vessel?
    • Vasculitis/inflammation?

Mnemonic: chorio, cord, vessels, villi (maturity, infarction).

Normal placenta

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS.

C-section

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CAESAREAN SECTION:
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS.

Cord pathology

Two vessel umbilical cord

  • AKA two vessel cord.
  • AKA single umbilical artery.
Main article: Two vessel umbilical cord

Insertion

Marginal insertion

Definition:

  • The umbilical cord is attached to the placental disc at its margin.

Prevalence:

  • Approximately 12% of placentas.[21]

Relevance:

  • None according to WMSP.[21]
    • In theory, the cord, dependent on its relation to the internal os, is at greater risk of injury (leading to vasa previa) and compression (fetal hypoxia). A retrospective study found cord position in relation to the internal os is predictive for vasa previa.[22]

Velamentous insertion

Definition:

  • The umbilical cord inserts into the fetal membranes.[21]
    • The vessels are not protected by Wharton's jelly.
      • Wharton's jelly = the connective tissue surrounding the vessels in the cord.

Details:[21]

  • 3/4 of the time the vessel also branch; in the remaining 1/4 the vessels stay together.

Relevance:

  • Increased risk of vasa previa.[22]

Sign out

PLACENTA, UMBILICAL CORDS AND FETAL MEMBRANES, BIRTH:
- THREE VESSEL UMBILICAL CORD WITH A VELAMENTOUS INSERTION, OTHERWISE WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI WITHIN NORMAL LIMITS.

Umbilical knot

  • AKA umbilical cord knot.
  • AKA cord knot.
  • AKA true knot.

General

Gross

Work-up:[24]

  • Diameter measures and colour on both sides of the knot.
  • Knot should be untied to assess for deformation of Wharton's jelly.
  • Sections from both sides of the knot - to look for thrombi.

Note:

  • False knots (large diameter - focally) are common - they cannot be untied.

Microscopic

Features:

  • +/-Thrombi.
    • Fibrin deposition.
  • +/-Lines of Zahn.

Images:

Coiling

  • Hypo- and hypercoiling are both considered problematic.[21]
    • Normal: 1-3 coils/10 cm.[25]
  • Associated with cord stricture, which is usu. at the fetal end of the cord.[26]

Notes:

  • There is little uniformity in how coiling is assessed in the medical literature - though 10% and 90% are considered the cut-points for normal.[27]
    • What are the 10% and 90% cut-points? They are not given in WMSP. UT access to a journal article[28] that might have it is screwed-up.

Cord hematoma

Features:[26]

  • Rare ~ 1/5500.
  • Mortality ~50% is severe.

Membranes

Amnion nodosum

Main article: Amnion nodosum

Placental meconium

Main article: Placental meconium

Squamous metaplasia of the amnion

General

  • Benign common finding thought to be of no clinical significance.[29]
  • Needs to be separated from amnion nodosum - important.[31]

Gross

Features:[32]

  • White (or yellow) plaques - irregular outline.

DDx:

Images:

Microscopic

Features:[32]

  • Dense, paucicellular (pink) compact keratin - key feature.

Image:

Circumvallate placenta

  • AKA circumvallate insertion of the membranes.

General

Note:

  • Membranes usually attach to the edge of the placenta.

Gross

  • Fetal membranes attach to the fetal surface of the placenta away from the margin of the placental disc.

Classification:

  • Partial - not circumferential.
  • Complete.

DDx:

Images:

Twin placentas

Main article: Twin placentas

These are often submitted... even if they are normal. In these specimens, usually, the chorion is the key.

It covers:

  • Monozygotic vs. dizygotic twins.
  • Twin-to-twin transfusion syndrome.

Placental disc

Villous edema

General

  • Non-specific finding.
  • Reported in associated with congenital adrenal hyperplasia for the stem villi.[35]

Microscopic

Features:

  • "Swiss chesse-like" appearance / bubbly appearance.
  • Usually patchy and focal.

Note:

  • Cistern formation is reported in the stem villi in association with congenital adrenal hyperplasia.[35]

DDx:

Image:

Placental villous immaturity

Main article: Placental villous immaturity

Villous hypoplasia

  • AKA terminal villus deficiency.[37]
Main article: Villous hypoplasia

Diseases of the placental attachment

Placenta creta

Includes placenta accreta, placenta increta, and placenta percreta.

Main article: Placenta creta

Placental abruption

Main article: Placental abruption

Inflammatory pathologies

Overview of infections

General:[38]

Types

By site:[38]

  • Fetal membranes: chorioamnionitis, membranitis.[39]
  • Umbilical cord: funisitis.
  • Placenta: placentitis, villitis.

Membranitis

Chorionitis redirects here.

General

Microscopic

Features:

  • PMNs in the decidua.
  • +/-PMNs in subamniotic tissue.
  • +/-Necrosis in decidua or chorion/subamniotic tissue.

Note:

DDx:

Grading membranitis

Sternberg:[39]

  1. PMNs - decidua only.
  2. PMNs - in subamniotic tissue.
  3. 1 or 2 + necrosis in decidua or chorion/subamniotic tissue.

Sign out

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, CESAERIAN SECTION:
- FETAL MEMBRANES WITH CHORIONITIS.
- THREE VESSEL UMBILICAL CORD WITH VASCULITIS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.

Waffle

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- FETAL MEMBRANES WITH MECONIUM-LADEN MACROPHAGES AND ABUNDANT DECIDUAL NEUTROPHILS
  SUSPICIOUS FOR EARLY CHORIONITIS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI.
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.

Chorioamnionitis

Main article: Chorioamnionitis

Umbilical cord vasculitis

Main article: Umbilical cord vasculitis

Funisitis

Main article: Funisitis
  • Inflammation of Wharton's jelly - the connective tissue of the umbilical cord.

Acute villitis

Main article: Acute villitis

Villitis of unknown etiology

Main article: Villitis of unknown etiology

Chronic intervillitis

General

  • Rare.
  • Massive chronic intervillitis - associated IUGR, spontaneous abortion, perinatal fetal death.[42]
  • Recurs.

Microscopic

Features:[41][42]

  • Intervillous inflammatory cells:
    • Lymphocytes.
    • Histiocytes.
  • Fibrinoid deposition.

Images

  • Intervillitis - intermed. mag. (WC)

  • Intervillitis - very high mag. (WC)

Chronic deciduitis

  • AKA plasma cell deciduitis.
Main article: Chronic deciduitis

Placental infarction

True infarcts

Main article: Placental infarct

Perivillous fibrin deposition

  • Abbreviation PFD.

General

  • Thought to be an immunologic problem - resulting in platelet activation and fibrin deposition.[43]
  • May be associated with diabetes mellitus.[44]

Gross

  • Pale (white).
  • Firm.
  • White fibrous sepatae.

Microscopic

Features:

  • Acellular eosinophilic material around formed villi.
  • Obliteration of intervillous space.
    • Intervillous distance increased vis-a-vis normal - key feature.

Notes:

  • Nuclei of villi are usually preserved.
  • Villi may have secondary infarction, i.e. there may be nuclear destruction (karyolysis, karyorrhexis, pyknosis).

DDx:

Images:

Sign out

Thrombi

PLACENTA, UMBILICAL CORD AND FETAL MEMBRANES, BIRTH:
- THREE VESSEL UMBILICAL CORD WITHIN NORMAL LIMITS.
- FETAL MEMBRANES WITHIN NORMAL LIMITS.
- PLACENTAL DISC WITH THIRD TRIMESTER VILLI AND THREE LARGE INTERVILLOUS 
THROMBI (BLOCKS A7-A9).

Maternal floor infarction

  • Abbreviated MFI.
  • Formally placental maternal floor infarction.
  • AKA massive perivillous fibrin deposition.[45]
Main article: Maternal floor infarction

Fetal disease

Fetal thrombotic vasculopathy

  • Abbreviated FTV.
  • A large number of terms are used for this including:[46]
    • Fibrinous vasculosis.
    • Fibromuscular sclerosis.
    • Fetal artery stem thrombosis.
  • The multitude of terms reflects the confusion about this finding and that it has numerous etiologies.[46]
Main article: Fetal thrombotic vasculopathy

Hemorrhagic endovasculitis

  • Abbreviated HEV.

General

  • Associated with stillbirth.[47]

Microscopic

Features:[48]

  • Walls of the (fetal) placental blood vessels (in the villi) are disrupted.
  • +/-Intraluminal necrotic debris.
  • RBC fragmentation.

Maternal disease

Hypertensive changes

General

Associated pathologic changes:[49]

  • Placental infarcts.
  • Increased syncytial knots.
  • Hypovascularity of the villi.
  • Cytotrophoblastic proliferation.
  • Thickening of the trophoblastic basement membrane.

Microscopic

Features:[49]

  • Enlarged endothelial cells - fetal capillaries.
  • Atherosis of the spiral arteries - placental bed (maternal).

Notes:

  • One should look for the changes in the membrane roll, not the maternal surface.[50]

Images:

Hypertrophic decidual vasculopathy

AKA decidual vasculopathy.
Main article: Hypertrophic decidual vasculopathy

HELLP syndrome

Main article: HELLP syndrome

Malaria

Main article: Malaria

General

  • Uncommon in Canada.
  • May lead to fetal demise.

Microscopic

Feature:

  • RBCs with basophilic dots ~1-2 micrometres.

Image

  • Maternal malaria - very high mag. (WC)

Tumours

Main article: Gestational trophoblastic disease

Chorangioma

Main article: Chorangioma

Chorangiomatosis

General

Associated with:

Gross

  • Multiple tan nodules.

Microscopic

Features:

  • Multiple chorangiomas - the difference between chorangioma and chorangiomatosis is not well defined.[51]

Images:

Chorangiosis

Main article: Chorangiosis

Other

Fetus papyraceus

  • May be spelled foetus papyraceus.
  • AKA fetus compressus.
Main article: Fetus papyraceus

Placental mesenchymal dysplasia

  • Abbreviated PMD.
Main article: Placental mesenchymal dysplasia

Placental cysts and pseudocysts

Types:[52]

  • Amnionic epithelial inclusion cyst (amniotic cyst).
  • Epidermal inclusion cyst - lined by keratinized squamous epithelium.
  • Chorionic cyst (AKA chorionic pseudocyts).
  • Cell island cyst.

Other considerations:[53]

  • Hematoma.
  • Fibrin-lined pseudocyst.

General:[53]

  • Usually good outcome.
  • Large cysts (>4.5 cm) or multiple cysts (>3) are associated with IUGR.

Images:

See also

References

  1. ↑ Sun, CC.; Revell, VO.; Belli, AJ.; Viscardi, RM. (Jun 2002). "Discrepancy in pathologic diagnosis of placental lesions.". Arch Pathol Lab Med 126 (6): 706-9. doi:10.1043/0003-9985(2002)1260706:DIPDOP2.0.CO;2. PMID 12033960.
  2. ↑ Yetter JF (March 1998). "Examination of the placenta". Am Fam Physician 57 (5): 1045–54. PMID 9518951.
  3. ↑ Hargitai B, Marton T, Cox PM (August 2004). "Best practice no 178. Examination of the human placenta". J. Clin. Pathol. 57 (8): 785–92. doi:10.1136/jcp.2003.014217. PMC 1770400. PMID 15280396. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770400/.
  4. ↑ URL: http://smj.sma.org.sg/5012/5012ra1.pdf. Accessed on: 11 February 2011.
  5. ↑ Sherman C. 8 February 2011.
  6. ↑ URL: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=5069. Accessed on: 7 July 2010.
  7. ↑ 7.0 7.1 7.2 7.3 Sternberg, Stephen S. (1997). Histology for Pathologists (2nd ed.). Lippincott Williams & Wilkins. pp. 974. ISBN 978-0397517183.
  8. ↑ Sternberg, Stephen S. (1997). Histology for Pathologists (2nd ed.). Lippincott Williams & Wilkins. pp. 977. ISBN 978-0397517183.
  9. ↑ Narasimha, A.; Vasudeva, DS.. "Spectrum of changes in placenta in toxemia of pregnancy.". Indian J Pathol Microbiol 54 (1): 15-20. doi:10.4103/0377-4929.77317. PMID 21393870.
  10. ↑ URL: http://zulekhahospitals.com/uploads/files/Sub-chorionic.pdf. Accessed on: 17 August 2012.
  11. ↑ J Anat. Soc. India 49(2) 149-152 (2000). Available at: http://www.indmedica.com/anatomy/aindex1.cfm?anid=41. Accessed on: January 21, 2009.
  12. ↑ Winters R, Waters BL (December 2008). "What is adequate sampling of extraplacental membranes?: a randomized, prospective analysis". Arch. Pathol. Lab. Med. 132 (12): 1920–3. PMID 19061291.
  13. ↑ Lester, Susan Carole (2005). Manual of Surgical Pathology (2nd ed.). Saunders. pp. 461. ISBN 978-0443066450.
  14. ↑ CS. 7 February 2011.
  15. ↑ AFIP Placental pathol. ISBN: 1-881041-89-1. P.312
  16. ↑ AFIP Placental pathol. ISBN: 1-881041-89-1. P.312
  17. ↑ Fox, Harold; Sebire, Neil J. (2007). Pathology of the Placenta (Major Problems in Pathology) (3rd ed.). Saunders. pp. 559-561. ISBN 978-1416025924.
  18. ↑ URL: http://quizlet.com/5793113/ob-flash-cards/. Accessed on: 13 January 2012.
  19. ↑ Clarson, C.; Tevaarwerk, GJ.; Harding, PG.; Chance, GW.; Haust, MD.. "Placental weight in diabetic pregnancies.". Placenta 10 (3): 275-81. PMID 2771897.
  20. ↑ Hindmarsh, PC.; Geary, MP.; Rodeck, CH.; Jackson, MR.; Kingdom, JC. (Aug 2000). "Effect of early maternal iron stores on placental weight and structure.". Lancet 356 (9231): 719-23. PMID 11085691.
  21. ↑ 21.0 21.1 21.2 21.3 21.4 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 464. ISBN 978-0781765275.
  22. ↑ 22.0 22.1 Hasegawa J, Farina A, Nakamura M, et al. (December 2010). "Analysis of the ultrasonographic findings predictive of vasa previa". Prenat. Diagn. 30 (12-13): 1121–5. doi:10.1002/pd.2618. PMID 20872421.
  23. ↑ 23.0 23.1 Airas U, Heinonen S (April 2002). "Clinical significance of true umbilical knots: a population-based analysis". Am J Perinatol 19 (3): 127–32. doi:10.1055/s-2002-25311. PMID 12012287.
  24. ↑ 24.0 24.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 464. ISBN 978-0781765275.
  25. ↑ CS. 7 February 2011.
  26. ↑ 26.0 26.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 465. ISBN 978-0781765275.
  27. ↑ Khong TY (December 2010). "Evidence-based pathology: umbilical cord coiling". Pathology 42 (7): 618–22. doi:10.3109/00313025.2010.520309. PMID 21080869.
  28. ↑ PMID 16076615.
  29. ↑ Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 463. ISBN 978-0781765275.
  30. ↑ Chew, RH.; Silberberg, BK. (Apr 1990). "Possible association of acute inflammatory exudate in chorioamnionitis and amniotic squamous metaplasia.". Am J Clin Pathol 93 (4): 582-5. PMID 2321592.
  31. ↑ CS. 7 February 2011.
  32. ↑ 32.0 32.1 32.2 Adeniran, AJ.; Stanek, J. (Dec 2007). "Amnion nodosum revisited: clinicopathologic and placental correlations.". Arch Pathol Lab Med 131 (12): 1829-33. doi:10.1043/1543-2165(2007)131[1829:ANRCAP]2.0.CO;2. PMID 18081444.
  33. ↑ URL: http://flylib.com/books/en/2.953.1.49/1/. Accessed on: 10 January 2011.
  34. ↑ Suzuki, S. (Feb 2008). "Clinical significance of pregnancies with circumvallate placenta.". J Obstet Gynaecol Res 34 (1): 51-4. doi:10.1111/j.1447-0756.2007.00682.x. PMID 18226129.
  35. ↑ 35.0 35.1 Furuhashi, M.; Oda, H.; Nakashima, T. (Sep 2000). "Hydrops of placental stem villi complicated with fetal congenital adrenal hyperplasia.". Arch Gynecol Obstet 264 (2): 101-4. PMID 11045335.
  36. ↑ URL: http://www.med.yale.edu/obgyn/kliman/placenta/articles/EOR_Placenta/Trophtoplacenta.html. Accessed on: 28 May 2011.
  37. ↑ Baergen, Rebecca N. (2011). Manual of Pathology of the Human Placenta (2nd ed.). Springer. pp. 346. ISBN 978-1441974938.
  38. ↑ 38.0 38.1 Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1106. ISBN 0-7216-0187-1.
  39. ↑ 39.0 39.1 Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Oberman, Harold A; Reuter, Victor E (2004). Sternberg's Diagnostic Surgical Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 2311. ISBN 978-0781740517.
  40. ↑ Vedovato, S.; Zanardo, V. (Jun 2010). "[Chorioamnionitis and inflammatory disease in the premature newborn infant].". Minerva Pediatr 62 (3 Suppl 1): 155-6. PMID 21090086.
  41. ↑ 41.0 41.1 Jacques, SM.; Qureshi, F. (Oct 1993). "Chronic intervillositis of the placenta.". Arch Pathol Lab Med 117 (10): 1032-5. PMID 8215826.
  42. ↑ 42.0 42.1 Rota, C.; Carles, D.; Schaeffer, V.; Guyon, F.; Saura, R.; Horovitz, J. (Nov 2006). "[Perinatal prognosis of pregnancies complicated by placental chronic intervillitis].". J Gynecol Obstet Biol Reprod (Paris) 35 (7): 711-9. PMID 17088773.
  43. ↑ Sebire, NJ.; Backos, M.; Goldin, RD.; Regan, L. (May 2002). "Placental massive perivillous fibrin deposition associated with antiphospholipid antibody syndrome.". BJOG 109 (5): 570-3. PMID 12066949.
  44. ↑ Baergen, Rebecca N. (2011). Manual of Pathology of the Human Placenta (2nd ed.). Springer. pp. 327. ISBN 978-1441974938.
  45. ↑ Baergen, Rebecca N. (2011). Manual of Pathology of the Human Placenta (2nd ed.). Springer. pp. 367. ISBN 978-1441974938.
  46. ↑ 46.0 46.1 Marchetti, D.; Belviso, M.; Fulcheri, E. (Mar 2009). "A case of stillbirth: the importance of placental investigation in medico-legal practice.". Am J Forensic Med Pathol 30 (1): 64-8. doi:10.1097/PAF.0b013e318187387e. PMID 19237859.
  47. ↑ Stevens NG, Sander CH (October 1984). "Placental hemorrhagic endovasculitis: risk factors and impact on pregnancy outcome". Int J Gynaecol Obstet 22 (5): 393–7. PMID 6151926.
  48. ↑ Sander CM, Gilliland D, Akers C, McGrath A, Bismar TA, Swart-Hills LA (February 2002). "Livebirths with placental hemorrhagic endovasculitis: interlesional relationships and perinatal outcomes". Arch. Pathol. Lab. Med. 126 (2): 157–64. PMID 11825110.
  49. ↑ 49.0 49.1 Soma H, Yoshida K, Mukaida T, Tabuchi Y (1982). "Morphologic changes in the hypertensive placenta". Contrib Gynecol Obstet 9: 58–75. PMID 6754249.
  50. ↑ Sherman, C. 7 February 2011.
  51. ↑ URL: http://path.upmc.edu/cases/case655/dx.html. Accessed on: 28 January 2012.
  52. ↑ Baergen, Rebecca N. (2011). Manual of Pathology of the Human Placenta (2nd ed.). Springer. pp. 219-220. ISBN 978-1441974938.
  53. ↑ 53.0 53.1 53.2 Brown, DL.; DiSalvo, DN.; Frates, MC.; Davidson, KM.; Genest, DR. (Jun 2002). "Placental surface cysts detected on sonography: histologic and clinical correlation.". J Ultrasound Med 21 (6): 641-6; quiz 647-8. PMID 12054300.

Recommended reading

External links

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