Choriocarcinoma

Epidemiology & Etiology:

• 50% arise in hydatiform moles
• 25% arise in previous abortions
• 22% arise in normal pregnancies
• Remainder in ectopic pregnancies, and genital and extragenital sites

Common sites:

• Uterus
• Tubes (ectopic pregnancy)
• Gonads
• Extragenital (midline)
• Mets to:
• Lungs
• Vagina
• Brain
• Liver
• Kidney

Gross features:

• No large, bulky mass

Histologic features:

• vague villiform pattern
• Purely epithelial
• No chorionic villi
• 2 populations of cells
• large purple multinuclear cells (syncitiotrophoblasts)
• smaller pink cells with defined cell borders (cytotrophoblasts)
• hemorrhage often associated
• necrosis is common
• lymphovascular invasion frequent
• significant if comprises > 5-10% of a mixed germ cell tumour

Immunophenotype:

Marker:	Sensitivity:	Specificity:
Beta-hCG	Good
Keratin

Molecular features:

Other features:

• Most aggressive of germ cell tumours
• Very good response to chemotherapy in gestational choriocarcinoma (near 100% cure)
• Non-gestational choriocarcinoma is much less responsive
• Presents as spotting usually
• Beta-HCG higher than hydatiform mole (usually)
• Some are hormonally inactive