[The primary mucinous adenocarcinoma of renal pelvis: a case report].

A case of primary mucinous adenocarcinoma of the renal pelvis is reported. A 55-year-old man visited our clinic with lumbar pain. He had a history of left renal stone and had left partial nephrectomy four years previously. Physical examination revealed a hard, child-head-sized, unmovable and uneven tumor in the left side of the abdomen. Intravenous pyelography revealed the non-functioning left kidney with calcification, in which hydronephrosis was detected by computed tomography. In transabdominal sonography a huge mass with mixed echo pattern was observed. Aspiration biopsy under interventional ultrasound was performed, aspirating yellow-white semi-transparent mucinous substance, which was highly suspicious of malignancy by cytology. He died 74 days after the first admission. Autopsy revealed primary mucinous adenocarcinoma of the renal pelvis. This was thought to be the 14th case of primary mucinous adenocarcinoma of the renal pelvis reported in the Japanese literature.