Gestational trophoblastic disease
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Gestational trophoblastic disease (GTD) includes choriocarcinoma and hydatidiform moles.
Overview
Most common
Overview of gestational trophoblastic disease:
Gross | Nuclear atypia | Villi | IHC | DNA content | Images | |
Complete mole | "snowstorm" | +/- ? | yes, all abnormal [1] | p57(KIP2) -ve | Paternal, diploid | Complete mole (pathconsultddx.com) |
Partial mole | grape-like clusters |
+/- | large villi, villi with cisterns, villi with cytotrophoblastic inclusions |
p57(KIP2) +ve | Maternal & paternal, tripoid | Partial mole (utah.edu) |
Choriocarcinoma | haemorrahagic, necrotic | marked | none | beta-hCG +ve | ? | Choriocarcinoma - testicular (webpathology.com) |
More comprehensive overview
Benign abnormal looking placenta:
- Placental site nodule (PSN).
- Exaggerated placental site (EPS).
Abnormal fertilization:
- Hydatidiform mole.
Tumours:
- Invasive mole.
- Choriocarcinoma.
- Placental site trophoblastic tumour (PSTT).
- Epithelioid trophoblastic tumour (ETT).
Choriocarcinoma
- Classified as a germ cell tumour.
- Usually a mixed tumour, i.e. pure choriocarcinoma is rare, e.g. dysgerminoma + choriocarcinoma.
Clinical/Epidemiology
- High beta-hCG.
- May be preceded by a complete hydatidiform mole.[2]
- More common in the far east.
- More common at extremes of fertile age (teens and 40-50 years).
Micro
- Nuclear pleomorphism - usually marked.
- Often haemorrhage.
- Syncytiotrophoblast surrounds nests of cytotrophoblast.
Image:
Notes:
- Its usually NOT choriocarcinoma if there are villi.[3]
IHC
- beta-hCG +ve.[4]
Hydatidiform moles
Types
- Partial mole.
- Complete mole.
Mole vs. normal
- Moles have large chorionic villi with edema and abnormal blood vessels.[5]
Etymology
- Hydatid is literally watery vesicle.[6]
IHC
- p57(KIP2) - the gene is strongly paternally imprinted and the paternal copy is inactived; its expression is from the maternal gene.
- Complete moles lacks the maternal genome; thus, p57(KIP2) immunostaining is absent.[7]
- Memory device: p57 is positive in partial moles.
Cytogenetics
- The type of mole can be determined by cytogenetics.[8]
Partial Mole
- Formal name: partial hydatidiform mole.
Genetics
- Polypoid - usually triploid (e.g. 69XXY).
Images: [2]
Histology
- Abnormal chorionic villi.
- Villi too large (>0.1 mm ?).
- Villi with cisterns.
- Contain fluid in the centre, i.e. are "hydropic".
- Villi with cytotrophoblastic inclusions.
- Cytotrophoblast in the core of a villus (normally it is only at the surface of the villus).
- May have fetal parts, such as nucleated RBCs.
- Trophoblastic proliferation - image - med.utah.edu.
- Without atypia.[9]
Images:
- partial mole - med.utah.edu.
- partial mole (several images) - gfmer.ch.
Complete Mole
- Formal name: complete hydatidiform mole.
- Also known as classic mole.
Epidemiology
- May precede choriocarcinoma.[10]
Genetics
- Diploid - most are 46XX.
- All male dervived, i.e. arise from DNA in sperm.
Microscopy
- No normal villi.
- No fetal parts seen.
Image:
Radiology
- "Snowstorm" appearance on ultrasound.[11]
Placental site trophoblastic tumour
- Abbreviated PSTT.
- Malignant counterpart of exaggerated placental site or EPS.
Clinical
- Raised beta-hCG - but usually not has high as in choriocarcinoma.[12]
- Derived from trophoblast - the stuff that forms the chorionic villi - remember: syncytiotrophoblasts (outer layer) and cytotrophoblasts (inner layer).
Epidemiology
- Usually follows a normal pregnancy ~ 75% of cases.[12]
Microscopic
Features:
- Large cells.
- Nuclear atypia.
- Cytoplasm - cytoplasmic.
- NC ratio ~ normal.
EPS vs. PSTT:
- EPS has a low MIB-1 (Ki-67).
Epithelioid trophoblastic tumour
- Abbreviated ETT.
- Often in endocervix.
- Malignant counterpart of placental site nodule or PSN.
Images:
DDx:
- Invasive squamous cell carcinoma.
Placental site nodule
- Benign.
Microscopic
Features:
- Small collection of cells that look similar to decidua (mnemonic NEW):
- Nucleus, central location.
- Eosinophilic cytoplasm.
- Well-defined cell borders.
Images:
DDx:
- Invasive squamous cell carcinoma.
- Can be sorted-out with IHC (SCC will typically be: p16 +ve, MIB-1 +ve).
See also
- Hydatid disease - due to Echinoccus spp. such as E. granulosus.
- Chorionic villi.
- Ectopic pregnancy.
- Placenta.
References
- ↑ http://pathologyoutlines.com/placenta.html#completemole
- ↑ PBoD PP.1110-1111.
- ↑ Notebook P.180. 21 September 2009.
- ↑ Kalhor N, Ramirez PT, Deavers MT, Malpica A, Silva EG (April 2009). "Immunohistochemical studies of trophoblastic tumors". Am. J. Surg. Pathol. 33 (4): 633–8. doi:10.1097/PAS.0b013e318191f2eb. PMID 19145204.
- ↑ URL: http://pathologyoutlines.com/placenta.html#hydatgeneral.
- ↑ URL: http://dictionary.reference.com/browse/hydatid.
- ↑ Merchant SH, Amin MB, Viswanatha DS, Malhotra RK, Moehlenkamp C, Joste NE (February 2005). "p57KIP2 immunohistochemistry in early molar pregnancies: emphasis on its complementary role in the differential diagnosis of hydropic abortuses". Hum. Pathol. 36 (2): 180–6. doi:10.1016/j.humpath.2004.12.007. PMID 15754295.
- ↑ http://jcp.bmjjournals.com/cgi/reprint/51/6/438.pdf
- ↑ http://pathologyoutlines.com/placenta.html#incompletemole
- ↑ PBoD P.1111.
- ↑ [1]
- ↑ 12.0 12.1 URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70463-6. Accessed on: 23 September 2009.