Placenta: Difference between revisions

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Mikael Häggström (talk | contribs)
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Mikael Häggström (talk | contribs)
Administrators, Editors, Image-reviewer, csmoderator, Interface administrators, Administrators, Upload Wizard campaign editors
7,148 edits
 
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{{Top
<noinclude>{{Top
|author1=[[User:Mikael Häggström|Mikael Häggström]]
|author1=[[User:Mikael Häggström|Mikael Häggström]]
|author2=
|author2=
}}
}}
{{Comprehensiveness}}
{{Comprehensiveness}}
 
</noinclude>
==Gross processing==
==Gross processing==
*Determine the '''shape''' of the placenta
*Determine the '''shape''' of the placenta
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*'''Weigh''' the trimmed disk, after having trimmed away the cord and membranes, and after having removed excess amounts of loose retroplacental blood clots over the maternal surface.
*'''Weigh''' the trimmed disk, after having trimmed away the cord and membranes, and after having removed excess amounts of loose retroplacental blood clots over the maternal surface.
*Examine the '''fetal surface''' (chorionic plate):
*Examine the '''fetal surface''' (chorionic plate):
:*Note its '''color'''  
:*Note its '''color''', in particular if it is green (often faint and tan-green, brown-green to yellow-green (which indicates '''[[Meconium histocytosis|meconium staining]]''').
:*Look for any '''pathologies''' including granular excrescences, subchorionic fibrin or subamniotic hemorrhage  
:*Look for any '''pathologies''' including granular excrescences, subchorionic fibrin or subamniotic hemorrhage  
:*Look at the integrity and extent of the '''vasculature''', including any traumatic damage. Also palpate the vasculature for any thrombosis. If a thrombus is grossly found for a live birth, the baby may have thrombosis, so the finding must immediately be reported to the clinician in care of the baby.
:*Look at the integrity and extent of the '''vasculature''', including any traumatic damage. Also palpate the vasculature for any thrombosis. If a thrombus is grossly found for a live birth, the baby may have thrombosis, so the finding must immediately be reported to the clinician in care of the baby.
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*Note the '''color''' of the parenchyma and describe any pale areas, cysts, thrombi, increased fibrin, calcifications and infarcts. For possible infarcts, estimate the total amount of infarcted tissue as a percentage of the placental volume. Infarction is clinically significant if it involves at least 5-10% of the placental volume.
*Note the '''color''' of the parenchyma and describe any pale areas, cysts, thrombi, increased fibrin, calcifications and infarcts. For possible infarcts, estimate the total amount of infarcted tissue as a percentage of the placental volume. Infarction is clinically significant if it involves at least 5-10% of the placental volume.
[[File:Gross pathology of placental disorders.jpg|thumb|520px|center|Gross pathology of placental disorders.<ref name="ChenZhang2020">{{cite journal|last1=Chen|first1=Yukun|last2=Zhang|first2=Zhuomin|last3=Wu|first3=Chenyan|last4=Davaasuren|first4=Dolzodmaa|last5=Goldstein|first5=Jeffery A.|last6=Gernand|first6=Alison D.|last7=Wang|first7=James Z.|title=AI-PLAX: AI-based placental assessment and examination using photos|journal=Computerized Medical Imaging and Graphics|volume=84|year=2020|pages=101744|issn=08956111|doi=10.1016/j.compmedimag.2020.101744}}<br>- Fig 5- available via license: Creative Commons Attribution 4.0 International.</ref>]]
[[File:Gross pathology of placental disorders.jpg|thumb|520px|center|Gross pathology of placental disorders.<ref name="ChenZhang2020">{{cite journal|last1=Chen|first1=Yukun|last2=Zhang|first2=Zhuomin|last3=Wu|first3=Chenyan|last4=Davaasuren|first4=Dolzodmaa|last5=Goldstein|first5=Jeffery A.|last6=Gernand|first6=Alison D.|last7=Wang|first7=James Z.|title=AI-PLAX: AI-based placental assessment and examination using photos|journal=Computerized Medical Imaging and Graphics|volume=84|year=2020|pages=101744|issn=08956111|doi=10.1016/j.compmedimag.2020.101744}}<br>- Fig 5- available via license: Creative Commons Attribution 4.0 International.</ref>]]
If you see a '''true knot''' (rather than "false knots" which are merely bulges or protuberances that may look like knots), report whether the diameter of the cord is significantly different before versus after the knot (which is a sign of constriction caused by the knot).


===Tissue selection===
===Tissue selection===
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*Placental section including '''maternal surface''' (full thickness if possible)
*Placental section including '''maternal surface''' (full thickness if possible)
*Any '''lesions''' or '''abnormalities'''
*Any '''lesions''' or '''abnormalities'''
Avoid taking placental sections near the margin
Avoid taking placental sections near the margin. {{Moderate-begin}}If transported or processed together with other cases, put the placental in thin-mesh cassettes or tissue bags to limit contamination{{Moderate-end}}.<ref group=note>Chorionic villi are promiscuous contaminants of other tissues, and may cause a false positive finding for a cassette containing products of conception.<br>- {{cite journal| author=Carll T, Fuja C, Antic T, Lastra R, Pytel P| title=Tissue Contamination During Transportation of Formalin-Fixed, Paraffin-Embedded Blocks. | journal=Am J Clin Pathol | year= 2022 | volume= 158 | issue= 1 | pages= 96-104 | pmid=35195717 | doi=10.1093/ajcp/aqac014 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=35195717  }} </ref>
 
Example report:
{|class=wikitable
| Container A. Labeled "bladder tumor". The specimen is received in formalin and consists of multiple fragments of tan-gray, friable soft tissue measuring about __ x __ x __ cm in aggregate. The specimen is entirely submitted for microscopic examination in __ cassettes.
|}


===Gross report===
===Gross report===
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File:Histopathology of fibrinoid necrosis of the placenta.jpg|Villous '''[[Fibrinoid necrosis of the placenta|fibrinoid necrosis]]'''. Only needs mention when severe {{Comprehensive-begin}}or moderate{{Comprehensive-end}}.
File:Histopathology of fibrinoid necrosis of the placenta.jpg|Villous '''[[Fibrinoid necrosis of the placenta|fibrinoid necrosis]]'''. Only needs mention when severe {{Comprehensive-begin}}or moderate{{Comprehensive-end}}.
File:Histopathology of chorangiosis.jpg|'''Chorangiosis''', an abundance of blood vessels within the chorionic villi.
File:Histopathology of chorangiosis.jpg|'''Chorangiosis''', an abundance of blood vessels within the chorionic villi.
File:Histopathology of placenta with increased syncytial knotting of chorionic villi, annotated.jpg|Increased syncytial knotting of chorionic villi, with two knots pointed out. Causes include both hypoxia and hyperoxia.<ref name="pmid17140657">{{cite journal| author=Heazell AE, Moll SJ, Jones CJ, Baker PN, Crocker IP| title=Formation of syncytial knots is increased by hyperoxia, hypoxia and reactive oxygen species. | journal=Placenta | year= 2007 | volume= 28 Suppl A | issue=  | pages= S33-40 | pmid=17140657 | doi=10.1016/j.placenta.2006.10.007 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17140657  }} </ref>
</gallery>
</gallery>


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Mild to moderate inflammation in the decidua alone can be ignored (as it is most commonly a physiological response and doesn't have a clinical significance for the fetus).
Mild to moderate inflammation in the decidua alone can be ignored (as it is most commonly a physiological response and doesn't have a clinical significance for the fetus).
{{Bottom}}
 
Example in a '''twin''' placenta:
{|class=wikitable
| Twin placenta, Caesarean section:
*Third trimester dichorionic, diamniotic twin placenta.
*Villous morphology histologically appropriate for gestational age.
*Placental weight approximately 25th percentile for gestational age.
*Two three-vessel umbilical cords.
*Negative for chorioamnionitis and funisitis.
|}
<noinclude>{{Bottom}}</noinclude>
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