Choriocarcinoma

Choriocarcinoma is a rare aggressive germ cell tumour.

Choriocarcinoma
Diagnosis in short
Choriocarcinoma. H&E stain.
LM	cytotrophoblasts, syncytiotrophoblast (often wrapped around the cytotrophoblasts) - multinucleated, hemorrhage (very common), necrosis (common)
LM DDx	mixed germ cell tumour, invasive hydatidiform mole, placental site trophoblastic tumour
IHC	beta-hCG +ve, CD10 +ve, p63 +ve, OCT3 -ve, GATA3 +ve, CK7 +ve
Gross	dark friable, hemorrhagic/necrotic-appearing mass with an invasive border
Grossing notes	orchiectomy grossing
Staging	testicular cancer staging
Site	ovary, testis, uterus
Associated Dx	complete hydatidiform mole
Clinical history	often preceded by pregnancy
Signs	testicular mass (male)
Symptoms	vaginal bleeding (female)
Prevalence	rare
Blood work	beta-hCG markedly elevated (usu. >10,000 IU)
Prognosis	often poor
Treatment	surgery and chemotherapy

General

• Aggressive clinical course.
• Usually a mixed tumour, i.e. pure choriocarcinoma is rare, e.g. dysgerminoma + choriocarcinoma.

Clinical

• High beta-hCG -- usually > 10,000 IU.
  • Median in one series of testicular choriocarcinoma ~ 200,000 IU.
  • Elevation may be seen in other (non-trophoblastic) tumours.
• Vaginal bleeding or testicular mass.
• Occasionally thyrotoxicosis.

Note:

• Beta-hCG is negative ~3 weeks after pregnancy.

Epidemiology

• May be preceded by a complete hydatidiform mole.
• More common in the far east.
• More common at extremes of fertile age (teens and 40-50 years).

Gross

• Dark, shaggy, focally hemorrhagic & friable/necrotic-appearing.
• Invasive border.

Microscopic

Features:

• Two cell populations:

1. Cytotrophoblasts - key feature.
   • Clear cytoplasm.
   • Polygonal shaped cells in cords/masses.
   • Distinct cell borders.
   • Single uniform nucleus.
2. Syncytiotrophoblasts - may be absent.
   • Large + many irreg. or lobular hyperchromatic nuclei.
   • Eosinophilic vacuolated cytoplasm (contains hCG).

• +/-Hemorrhage - classically in the centre of the lesion.
• +/-Necrosis.

Notes:

• No chorionic villi should be present.
  • If chorionic villi are present... it is likely a type of hydatidiform mole.
• The dual cell population may not be evident at first.
  • Hemorrhage and marked nuclear pleomorphism are suggestive of the diagnosis.

DDx:

• Invasive hydatidiform mole.
• Placental site trophoblastic tumour (PSTT).
• Mixed germ cell tumour - esp. for testicular and ovarian tumours.

Images

Case

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  Choriocarcinoma - intermed. mag. (WC/Nephron)

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  Choriocarcinoma - high mag. (WC/Nephron)

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  Choriocarcinoma - very high mag. (WC/Nephron)

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  Choriocarcinoma - high mag. (WC/Nephron)

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  Choriocarcinoma - very high mag. (WC/Nephron)

Case

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  Choriocarcinoma - low mag. (WC)

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  Choriocarcinoma - intermed. mag. (WC)

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  Choriocarcinoma - high mag. (WC)

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  Choriocarcinoma - high mag. (WC)

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  Choriocarcinoma - very high mag. (WC)

www

• Choriocarcinoma - low mag. (webpathology.com).
• Choriocarcinoma (webpathology.com).
• Choriocarcinoma (webpathology.com).
• Choriocarcinoma (chestjournal.chestpubs.org).
• Choriocarcinoma - uterus (med.jhmi.edu).

IHC

ISUP consensus paper by Ulbright et al.:

• Beta-hCG +ve.
• Glypican 3 +ve/-ve.
• OCT3 -ve.
• AFP -ve.

Others:

• p63 +ve.
  • Placental site nodule and epithelioid trophoblastic tumour +ve.
  • Exaggerated placental site and placental site trophoblastic tumour -ve.
• Ki-67 +ve -- typically >30%.
• CK7 +ve.
• MUC-4 +ve.
• CD10 +ve (10 +ve of 10 cases).
• GATA3 +ve.

Notes:

• Beta-hCG is classically said to be produced by syncytiotrophoblasts.
  • Cytotrophoblasts also produce some - usually no staining.

See also

• Germ cell tumours.
• Ovarian tumours.
• Gynecologic pathology