腎杯内に突出した腎平滑筋腫

RENAL LEIOMYOMA PROJECTED INTO THE RENAL CALYX

　23歳，女性。肉眼的血尿を主訴として腎杯内に突出した腎平滑筋腫の1例を報告する。腎部分切除術を施行し，腫瘍は2×1.5×2cmの大きさで，病理組織学的には平滑筋腫と診断されたが，一部に核分裂像を示す細胞も認められ，境界悪性と考えられた。腎平滑筋腫は稀な疾患で，自験例を含め18例に過ぎない。

A case of renal leiomyoma projected into the renal calyx in a 23-year-old woman, complaining macrohematuria is reported. Right partial nephrectomy was performed. The tumor was 2 × 1.5 × 2 cm in size and was proved to be leiomyoma of the kidney histopathologically, but was considered to have border-line malignancy because of cellular mitosis involution. Renal leiomyoma is rare and only 18 cases including our case was collected in the Japanese literature.