Difference between revisions of "Placenta"

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=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.
#Increased numbers of villi with 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.
 
Note:
*‡ The normal number is dependent on the gestational age:<ref name=pmid20017638>{{Cite journal  | last1 = Loukeris | first1 = K. | last2 = Sela | first2 = R. | last3 = Baergen | first3 = RN. | title = Syncytial knots as a reflection of placental maturity: reference values for 20 to 40 weeks' gestational age. | journal = Pediatr Dev Pathol | volume = 13 | issue = 4 | pages = 305-9 | month =  | year =  | doi = 10.2350/09-08-0692-OA.1 | PMID = 20017638 }}</ref>
<center>
{| class="wikitable sortable"
! Gestational age
! Villi with knots<br> (average)
! Villi with knots<br> (range)
|-
| 40 weeks
| 29 %
| 27-36 %
|-
| 39 weeks
| 29 %
| 23-34%
|-
| 38 weeks
| 27 %
| 23-33 %
|-
| 37 weeks
| 28 %
| 24-33 %
|-
| 36 weeks
| 23 %
| 20-26 %
|-
| 35 weeks
| 22 %
| 15-32 %
|-
| 34 weeks
| 18 %
| 12-22 %
|-
| 32 weeks
| 13 %
| 10-16 %
|-
| 30 weeks
| 13 %
| 10-17 %
|-
| 26 weeks
| 11 %
| 10-13 %
|-
| 22 weeks
| 7 %
| 5-9 %
|}
</center>
 
====Images====
<gallery>
Image:Placental_infarct_-_low_mag.jpg | Placental infarct - low mag. (WC)
Image:Placental_infarct_-_intermed_mag.jpg | Placental infarct - intermed. mag. (WC)
</gallery>
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)].
 
===Sign out===
<pre>
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 TWO PLACENTAL INFARCTS (0.6 CM AND
  0.4 CM IN MAXIMAL DIMENSION).
</pre>
 
====Increased syncytial knots====
<pre>
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 WITH FOCALLY INCREASED SYNCYTIAL KNOTS,
  AND MILD PERIVILLOUS FIBRIN DEPOSITION, OTHERWISE WITHIN NORMAL LIMITS.
</pre>


==Perivillous fibrin deposition==
==Perivillous fibrin deposition==
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