[A case of thyroid cancer metastasizing to the bilateral kidneys].

A 66-year-old woman was admitted with a chief complaint of macroscopic hematuria. She had a past history of mediastinal tumor that had been surgically treated 11 years earlier and had been pathologically diagnosed as papillary thyroid cancer. Enhanced computed tomography demonstrated slightly enhanced renal tumors in both kidneys. Endoscopic findings showed bleeding from the left ureteral orifice. To control macroscopic hematuria, left nephrectomy was performed. Since, two months late severe bleeding occurred from the right ureteral orifice, right nephrectomy was performed and hemodialysis was initiated. The pathological findings of the bilateral renal tumors were papillary thyroid cancer suggesting metastases from the primary mediastinal tumor.