[Case report of rhabdoid tumor of the kidney occurring in own kidney following kidney transplantation from the living relative].

The patient was a 30-year-old man who had undergone living-donor kidney transplantation for renal failure caused by IgA nephropathy at age 29. On post-transplantation day 83, he visited our department with a chief complaint of asymptomatic hematuria. CT performed on post-transplantation day 95 revealed a tumor (size, 4 cm) in the right native kidney that had not been observed at the time of transplantation. CT performed on post-transplantation day 153 showed that the tumor had enlarged to 6 cm, while retrograde pyelogram performed on post-transplantation day 171 was negative for renal pelvic tumor. On post-transplantation day 193, radical right nephrectomy was performed. The tumor had directly invaded the diaphragm and the lower surface of the liver, and was histopathologically diagnosed as rhabdoid tumor of the kidney. As the pathological tissue was extremely malignant, hepatic posterior segmentectomy, right adrenalectomy, and lymph node dissection were further performed for metastases on post-transplantation day 200. On the 23rd day after radical right nephrectomy (post-transplantation day 216), the patient developed dyspnea. Chest CT showed pleural effusion, hemothorax in right lung and metastases in both lungs. The patient's general status gradually worsened thereafter, and he died on the 53rd day after radical right nephrectomy (post-transplantation day 246). Rhabdoid tumor of the kidney is a rare renal tumor that affects children, and only four adult cases have been reported to date. We report our experience with this rare case.