Non-palpable testicular embryonal carcinoma diagnosed by ultrasound: a case report.

With the extensive use of scrotal ultrasound (US), incidental non-palpable testicular tumors have thus been unexpectedly discovered. This report documents the case of 24-year-old male with a non-palpable testicular tumor that contained non-seminomatous germ cell components detected by US. Radical orchiectomy was performed and histological examinations confirmed a diagnosis of a mixed tumor of seminoma and embryonal carcinoma. Serum alpha-fetoprotein (AFP) rose from 7.8 to 43 ng/ml and CT scan revealed multiple metastases only 1 month after the operation. Systemic chemotherapy was introduced immediately, and the serum level of AFP decreased to the normal range and the metastatic lesions had disappeared after three courses of the chemotherapy. No recurrence was observed at 18 months follow-up after the chemotherapy. This is the first case of non-palpable testicular embryonal carcinoma, which metastasized soon after the resection. The obscurity and implications of such a diagnosis are also discussed.