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Difference between revisions of "Placenta"
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**Disc. | **Disc. | ||
**Length of cord, diameter of cord. | **Length of cord, diameter of cord. | ||
*Mass (weight) | **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 | *Umbilical cord | ||
**Attachment. | **Attachment. | ||
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**Knots (false vs. true). | **Knots (false vs. true). | ||
***False knots are nothing to worry about -- look like a knot but aren't really one. | ***False knots are nothing to worry about -- look like a knot but aren't really one. | ||
**Twisting/coiling. | **Twisting/coiling - 1-3 coils/10 cm is normal. | ||
**Number of vessels. | **Number of vessels. | ||
***Normal: 2 arteries, 1 vein. | ***Normal: 2 arteries, 1 vein. | ||
*Membranes - shiny, | *Membranes - shiny & translucent - normal (green, opaque/dull - chorioamnionitis). | ||
**Attachment: marginal (normal), circummarginate (inside edge), circumvallated (folding on self). | **Attachment: marginal (normal), circummarginate (inside edge), circumvallated (folding on self). | ||
**Site of rupture - if obvious; low point of rupture suggests low-lying placenta. | |||
*Placental disc. | *Placental disc. | ||
**Fetal surface - normal is shinny | **Fetal surface - normal is shinny. | ||
**Maternal surface | ***Dull in chorioamnionitis. | ||
**Maternal surface | |||
***Are the cotyledons intact? | |||
***Adherent clot? | |||
**Parenchyma - after sectioning: | |||
***White vs. red nodules. | |||
Notes: | |||
*Parenchymal nodules - a brief DDx: | |||
**White: infarct (chronic), thrombi, chorangioma, perivillous fibrin deposition. | |||
**Red: infarct (acute), thrombi. | |||
==Sections== | ==Sections== | ||
#Cord two sections. | |||
#Membranes (rolled). | |||
#Cord at insertion + disc. | |||
#Placenta - full thickness (maternal and fetal surface). | |||
#*Sections should not be taken at the margin of the disc. | |||
==Placental membranes== | ==Placental membranes== | ||
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*Meconium - green. | *Meconium - green. | ||
*Amnion nodosum - yellow patches. | *Amnion nodosum - yellow patches. | ||
**Some describe 'em as white.<ref>CS. 7 February 2011.</ref> | |||
==Placental mass== | ==Placental mass== | ||
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=Cord pathology= | =Cord pathology= | ||
*Two vessel cord. | *Two vessel cord. | ||
*Hypercoiling. | *Hypercoiling/Hypocoiling. | ||
*Abnormal insertion. | *Abnormal insertion. | ||
*Cord knots (true vs. false). | *Cord knots (true vs. false). | ||
*Strictures. | *Strictures. | ||
*Hematoma. | *Hematoma. | ||
*Hemangioma. | |||
*Benign cyst. | |||
==Two vessel cord== | ==Two vessel cord== | ||
*[[AKA]] single umbilical artery. | *[[AKA]] single umbilical artery. | ||
===Associations=== | |||
*Associated with congenital abnormalities, esp. cardiac - '''key point'''.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | *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 in early in gestation). | **Thought to be an acquired defect (as prevalence is lower in early in gestation). | ||
*May be seen in association of other cord abnormalities (e.g. marginal insertion, velamentous insertion). | *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: | Image: | ||
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==Coiling== | ==Coiling== | ||
*Hypo- and hypercoiling are both considered problematic.<ref name=Ref_WMSP464>{{Ref WMSP|464}}</ref> | |||
**Normal: 1-3 coils/10 cm.<ref>CS. 7 February 2011.</ref> | |||
*Associated with cord stricture, which is usu. at the fetal end of the cord.<ref name=Ref_WMSP465>{{Ref WMSP|465}}</ref> | |||
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.<ref name=pmid21080869>{{cite journal |author=Khong TY |title=Evidence-based pathology: umbilical cord coiling |journal=Pathology |volume=42 |issue=7 |pages=618–22 |year=2010 |month=December |pmid=21080869 |doi=10.3109/00313025.2010.520309 |url=}}</ref> | *There is little uniformity in how coiling is assessed in the medical literature - though 10% and 90% are considered the cut-points for normal.<ref name=pmid21080869>{{cite journal |author=Khong TY |title=Evidence-based pathology: umbilical cord coiling |journal=Pathology |volume=42 |issue=7 |pages=618–22 |year=2010 |month=December |pmid=21080869 |doi=10.3109/00313025.2010.520309 |url=}}</ref> | ||
**What are the 10% and 90% cut-points? They are not given in WMSP. UT access to a journal article<ref name=pmid16076615>PMID 16076615.</ref> that might have it is screwed-up. | **What are the 10% and 90% cut-points? They are not given in WMSP. UT access to a journal article<ref name=pmid16076615>PMID 16076615.</ref> that might have it is screwed-up. | ||
==Cord hematoma== | ==Cord hematoma== | ||
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==Amnion nodosum== | ==Amnion nodosum== | ||
===General=== | ===General=== | ||
*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> | *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=== | ===Gross=== | ||
*Yellow patch or yellow nodules. | *Yellow patch or yellow nodules. | ||
**Some think they are white.<ref>CS. 7 February 2011.</ref> | |||
Image: [http://www.webpathology.com/image.asp?n=2&Case=659 Amnion nodosum (webpathology.com)]. | Image: [http://www.webpathology.com/image.asp?n=2&Case=659 Amnion nodosum (webpathology.com)]. | ||
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===General=== | ===General=== | ||
*Associated with fetal distress. | *Associated with fetal distress. | ||
*Small amount - at term - is considered to be normal. | |||
===Gross=== | ===Gross=== | ||
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===Microscopy=== | ===Microscopy=== | ||
Features:<ref>ALS. 6 | Features:<ref>ALS. 6 Febraury 2009.</ref> | ||
*Macrophages with brown fine granular pigment. | *Meconium histiocytes - '''key feature'''. | ||
* | **Macrophages with brown fine granular pigment. | ||
*"Drop-out" of individual | *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 h - no staining of membranes. | ||
*1-3 h - amnion is stained. | *1-3 h - amnion is stained. | ||
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DDx: | DDx: | ||
*Hemosiderin-laden macrophages. | *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: | Images: | ||
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*Hemosiderin stain -- +ve for old blood. | *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> | **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> | *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> | ||
==Squamous metaplasia== | ==Squamous metaplasia== | ||
*Benign common finding - no clinical significance.<ref name=Ref_WMSP463>{{Ref WMSP|463}}</ref> | *Benign common finding - no clinical significance.<ref name=Ref_WMSP463>{{Ref WMSP|463}}</ref> | ||
*Needs to be separated from amnion nodosum.<ref>CS. 7 February 2011.</ref> | |||
Image: | Image: | ||
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=Twin placentas= | =Twin placentas= | ||
These are often submitted... even if they are normal. | These are often submitted... even if they are normal. In these specimens, usually, the chorion is the key. | ||
==General== | ==General== | ||