Metastasis to the kidney from a B2 thymoma: report of a case.

Thymomas are tumors with an indolent behavior and long clinical course, usually confined to the anterior mediastinum. Local recurrence is frequent while distant metastases are extremely rare. We report an unusual case of a B2 thymoma with a single renal metastasis The challenge in this case was the frozen section intraoperative diagnosis because of the clinical suspicion of malignant lymphoma. This report also highlights the role of surgical removal of solitary metastases.