Gestational trophoblastic disease
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:
Tumours:
- Invasive mole.
- Choriocarcinoma.
- Placental site trophoblastic tumour (PSTT).
- Epithelioid trophoblastic tumour (ETT).
Choriocarcinoma
General
- 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).
Microscopic
Features:
- 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
General
- Significance: increased risk for choriocarcinoma (in complete moles).
- Non-neoplastic proliferation.
Etymology:
- Hydatid is literally watery vesicle.[5]
Types
- Partial mole - see partial mole.
- Complete mole - see complete mole.
Microscopic
Hydropic changes:
| Entity | Villi (outline) | Cisterns | Blood vessels | Nucleated RBCs | p57 / Ki-67[6] staining | Ploidy | Image |
| Complete mole | bizarre; often not ovoid; fissures/slit-like gaps | well-developed | canalicular (thin walled) / few (???) | rare | -ve / ~70% | diploid / tetraploid | [1], [2], [3], [4] |
| Partial mole | jagged, still quasi ovoid | poorly developed / small | present | common | +ve / ~70% | triploid | [5], [6] |
| Hydropic abortus | smooth | poorly developed / small | common | common | +ve / ~20% | diploid | [7] |
![[1]](http://commons.wikimedia.org/wiki/File:Hydatidiform_mole_%281%29_complete_type.jpg){kind=link}
![[2]](http://commons.wikimedia.org/wiki/File:Hydatidiform_mole_%282%29_complete_type.jpg){kind=link}
![[3]](http://commons.wikimedia.org/wiki/File:Hydatidiform_mole_%283%29_complete_type.jpg){kind=link}
![[4]](http://commons.wikimedia.org/wiki/File:Hydatidiform_mole_%284%29_complete_type.jpg){kind=link}
Mole vs. normal
- Moles have large chorionic villi with edema and abnormal blood vessels.[7]
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.[8]
- Memory device:
- p57 is positive in partial moles.
- 3 Ps - partial moles are triploid.
Molecular
- The type of mole can be determined by cytogenetics.[9]
Partial Mole
- Formal name: partial hydatidiform mole.
General
Genetics:
- Polypoid - usually triploid (e.g. 69XXY).
Images: [8]
Microscopic
Features:
- 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.
- Without atypia.[10]
- "Norwegian fjord periphery"[11] - jagged border / irregular sawtooth-like periphery.
- Complete moles tend to have a smooth border
Images:
Complete Mole
- Formal name: complete hydatidiform mole.
- Also known as classic mole.
General
Epidemiology:
- May precede choriocarcinoma[12] ~ 1-2% risk.
Genetics:
- Diploid - most are 46XX.
- Male derived, i.e. arise from DNA in sperm; empty egg fertilized.
Radiology
- "Snowstorm" appearance on ultrasound.[13]
Microscopic
Features:
- No normal villi.
- No fetal parts seen.
- Very rarely nucleated RBCs.
Image:
Placental site trophoblastic tumour
- Abbreviated PSTT.
- Malignant counterpart of exaggerated placental site (abbreviated EPS).
Clinical
- Raised beta-hCG - but usually not has high as in choriocarcinoma.[14]
- 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.[14]
Microscopic
Features:
- Large cells.
- Nuclear atypia.
- Cytoplasm - cytoplasmic.
- NC ratio ~ normal.
EPS vs. PSTT:
- EPS has a low MIB-1 (Ki-67).
Images:
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
General
- 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
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1110-1111. ISBN 0-7216-0187-1.
- ↑ 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://dictionary.reference.com/browse/hydatid.
- ↑ URL: http://www.ihcworld.com/_newsletter/2003/focus_mar_2003.pdf. Accessed on: 28 May 2011.
- ↑ URL: http://pathologyoutlines.com/placenta.html#hydatgeneral.
- ↑ 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
- ↑ URL: http://pathologyoutlines.com/placenta.html#incompletemole. Accessed on: 9 August 2011.
- ↑ Howat, AJ.; Beck, S.; Fox, H.; Harris, SC.; Hill, AS.; Nicholson, CM.; Williams, RA. (Jul 1993). "Can histopathologists reliably diagnose molar pregnancy?". J Clin Pathol 46 (7): 599-602. PMID 8157742. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC501384/?page=3.
- ↑ Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1111. ISBN 0-7216-0187-1.
- ↑ URL:http://www.jultrasoundmed.org/cgi/content/abstract/18/9/589. Accessed on: 27 July 2010.
- ↑ 14.0 14.1 URL: http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675(06)70463-6. Accessed on: 23 September 2009.