[18F]FDG PET/CT in Metastatic Extragonadal Choriocarcinoma.

Extragonadal choriocarcinoma in men is an extremely rare and highly aggressive malignancy. Inconclusive biopsies due to a high necrotic component often delay diagnosis. Here is such a case, in which suggestive imaging findings on [18F]FDG PET/CT, a raised level of serum β-human chorionic gonadotropin, and gynecomastia clinched the diagnosis.