Résumé
Nonseminomatous germ cell tumors (GCTs) represent 60% of all GCTs, the most common malignancy in young men. Extragonadal primary GCTs are a rare entity and their origin remains unclear. F-18 fluorodeoxyglucose positron emission tomography (PET) is a promising imaging tool for GCT staging and treatment evaluation. We report the case of a 23-year-old man presenting with retroperitoneal primary choriocarcinoma associated with pulmonary and hepatic metastases. In addition to conventional imaging techniques, the F-18 fluorodeoxyglucose PET evaluation at staging and after chemotherapy improved the management of this patient. Particularly, PET findings before surgery were correlated with histologic results.