Difference between revisions of "Trophoblast"
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(→Trophoblast table: +age of villi table) |
(→Villi and age - table: more) |
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==Villi and age - table== | ==Villi and age - table== | ||
{| class="wikitable" | {| class="wikitable" | ||
| Gestational age | | '''Gestational age''' | ||
| Nucleated | | '''Nucleated [[RBC]]s''' | ||
| Cytotrophoblast / syncytiotrophoblast | | '''Cytotrophoblast / <br>syncytiotrophoblast''' | ||
| Villi size | | '''Villi size''' | ||
| Vessels | | '''Vessels''' | ||
| '''Other''' | |||
|- | |- | ||
| First trimester | | First trimester | ||
| Line 141: | Line 142: | ||
| large | | large | ||
| few; location central | | few; location central | ||
| | |||
|- | |- | ||
| Second trimester | | Second trimester | ||
| rare | | rare | ||
| cytotrophoblast difficult to identify | | cytotrophoblast difficult to identify; syncytial knots uncommon | ||
| intermediate | | intermediate | ||
| intermediate; location: central/periphery | | intermediate; location: central/periphery | ||
| | |||
|- | |- | ||
| Third trimester | | Third trimester | ||
| absent | | absent | ||
| cytotrophoblast indistinct | | cytotrophoblast indistinct; syncytial knots common | ||
| small | | small | ||
| abundant; location: periphery of villi | | abundant; location: periphery of villi | ||
| focal calcifications | |||
|} | |} | ||
Revision as of 14:19, 8 February 2011
Chorionic villi are part of a normal pregnancy. They are derived from the conceptus, i.e. NOT maternal.
Tumours arising from the trophoblast are dealt with in gestational trophoblastic disease.
Chorionic villi 101
- Maternal blood is around villi.
- Fetal blood (nucleated (fetal) RBCs) in the villi.
Basic histology
- Outer layer of villus / closer to mother : syncytiotrophoblasts.
- Inner layer of villus / closer to fetus : cytotrophoblasts.
Chorionic villi 102
- Syncytiotrophoblasts (eosinophilic cytoplasm with vacuoles (contain hCG), multiple hyperchromatic nuclei).
- Large + many irreg. or lobular hyperchromatic nuclei.
- Eosinophilic vacuolated cytoplasm (contains hCG).
- Closest to mom - covers cytotrophoblast.[1]
- Cytotrophoblasts (polygonal shape, distinct borders, clear cytoplasm, in cords, single nucleus).
- Polygonal shaped cells in cords/masses.
- Distinct cell borders.
- Covered by syncytiobrophoblast[2] - closer to fetus than syncytiotrophoblasts.
- Clear cytoplasm.
- Single uniform nucleus.
Intermediate trophoblast
General
- Abbreviated: IT.
- Thought to be the cell of origin for:[3]
- Exaggerated placental site (EPS).
- Placental site nodule (PSN).
- Placental site trophoblastic tumor (PSTT).
- Epithelioid trophoblastic tumor (ETT).
Subtypes
Three subtypes of IT are recognized:[3]
- Implanation site IT.
- Villous IT.
- Chorionic-type IT.
Microscopic
Features:
- Large cells.
- Eosinophilic cytoplasm.
- May be multi-nucleated.
IHC
Features:[4]
- hPL (human placental lactogen) +ve.
- beta-hCG -ve.
- Keratin +ve.
- EMA +ve in 2nd & 3rd trimester.
Notes:
- Cytotrophoblast and syncytiotrophoblast - keratin +ve.[4]
Age of villi
Young villi
- Do not have blood vessels.
- No syncytial knots.
Old villi
- Blood vessels present and at the periphery of villus - contain nucleated (fetal) RBCs.
- Syncytial knots.
Trophoblast table
Based on Shih et al.:[3]
| Cytotrophoblast | Syncytiotrophoblast | Villous intermediate trophoblast |
Implanation site intermediate trophoblast |
Chorionic-type intermediate trophoblast | |
| Nuclear features | round, small | multinucleated | polyhedral | pleomorphic +/-multinucleation (occasional), +/-nucleoli |
round / polyhedral |
| Cell borders | well-defined | poorly defined (?) | well-defined | moderately-defined | poorly defined (?) |
| Cytoplasm | minimal, clear to granular | abundant, vacuolated | abundant & eosinophilic to clear | abundant & eosinophilic | abundant & eosinophilic |
| Location | villi - deep to syncytiotrophoblast |
villi - superficial to cytotrophoblast - nearest to maternal blood |
villi | implanatation site | chorion |
| Function | stem cell | produces hormones | ??? | anchor placenta | ??? |
| IHC | beta-hCG ??? | beta-hCG | ??? | inhibin+, hPL+, beta-hCG-[4] | ??? |
| Image | [1] |
![[1]](http://commons.wikimedia.org/wiki/File:Intermediate_trophoblast_-_high_mag.jpg){kind=link}
hPL = human placental lactogen.
Notes:
- Keratin is positive in all trophoblastic tissue and negative in decidual tissue.[4]
Villi and age - table
| Gestational age | Nucleated RBCs | Cytotrophoblast / syncytiotrophoblast |
Villi size | Vessels | Other |
| First trimester | present | both can be identified | large | few; location central | |
| Second trimester | rare | cytotrophoblast difficult to identify; syncytial knots uncommon | intermediate | intermediate; location: central/periphery | |
| Third trimester | absent | cytotrophoblast indistinct; syncytial knots common | small | abundant; location: periphery of villi | focal calcifications |
See also
References
- ↑ http://upload.wikimedia.org/wikipedia/commons/4/45/Gray37.png
- ↑ http://upload.wikimedia.org/wikipedia/commons/4/45/Gray37.png
- ↑ 3.0 3.1 3.2 Shih IM, Kurman RJ (January 2001). "The pathology of intermediate trophoblastic tumors and tumor-like lesions". Int. J. Gynecol. Pathol. 20 (1): 31–47. PMID 11192071.
- ↑ 4.0 4.1 4.2 4.3 Yeh IT, O'Connor DM, Kurman RJ (May 1990). "Intermediate trophoblast: further immunocytochemical characterization". Mod. Pathol. 3 (3): 282–7. PMID 1694585.
