Case of extragonadal germ cell tumor mimicking left adrenal tumor.

A 30-year-old man presented to his previous physician with left abdominal pain. Computed tomography revealed a left retroperitoneal mass with calcification, measuring 15 × 9 × 6 cm, and the patient was referred to our hospital for further examination. Based on the endocrinologic examination and magnetic resonance imaging results, the patient was diagnosed with a nonfunctional left adrenal tumor, and laparoscopic left adrenalectomy was performed. Histopathology revealed well-defined boundaries between the tumor and the left adrenal gland, and the tumor was diagnosed as a non-seminoma consisting mainly of an immature teratoma with germ cell neoplasm in situ.