Renin-producing germ cell tumor in the pineal apparatus and mediastinum: A rare case report.

Ectopic extrarenal renin-producing tumor is a rare disease with approximately 30 case reports in English literature. We herein present the first case of renin-producing germ cell tumors in the pineal apparatus and mediastinum. A 26-year-old man who had undergone craniotomy for the treatment of pineal tumor was found to have hypertension at a regular visit postoperatively. Laboratory findings revealed high plasma levels of renin activity and that of aldosterone concentration. Chest computed tomography demonstrated a large tumor in the mediastinum. The pathological findings revealed the mediastinal germ cell tumor positive for renin. The present case suggests that for young patients presenting with hypertension with a mediastinal tumor, the possibility of a renin-producing tumor should be considered.