American Urological Association - Choriocarcinoma
- Pure choriocarcinoma is very rare and accounts for <1% of GCTs.
- Usually is mixed with other GCT components (8% of mixed GCT).
- May present with symptoms due to the metastatic lesions (hemoptysis, CNS symptoms) from hematogenous spread with subsequent detection of primary.
- Marked elevation in serum hCG (usually >100,000 mIU/mL).
- Gross: hemorrhagic nodule within the testicular parenchyma (image A); may only be a residual focus of scarring if the tumor has regressed.
- Classic choriocarcinoma
- Mixture of cytotrophoblasts (polygonal cells with clear cytoplasm, bland nucleus and prominent cell border) and syncitiotrophoblasts (multinucleated degenerate-appearing cells with abundant eosinophilic cytoplasm) (image B) & (image C).
- Syncytiotrophoblasts wrap or cap around mononuclear cytotrophoblastic cells and form villous configuration.
- Almost invariable associated with hemorrhages (search in these area).
- Monophasic choriocarcinoma
- Very rare, usually in metastatic sites; squamous-like features.
- Placental site trophoblastic tumor
- Very rare, composed of intermediated trophoblasts.
- Immunohistochemistry: hCG+ (image D), HPL+, and glypican-3+ (only syncytiotrophoblasts).
- Prognosis poorer than other GCTs, if pure.
- Some patients do fairly well with chemotherapy; metastatic disease spreads hematogenously, especially to lungs, brain, and GI tract.