[A case of upper urinary tract metastases from sigmoid colon cancer].

We report a case of colorectal cancer with metastasis to the upper urinary tract. A 56-year-old man had left flank pain. Ultrasonography and computed tomographic (CT) examination demonstrated left hydronephroureter and a soft-tissue structure within the left ureter. Urinary cytology of the left ureter showed class IIIb. We diagnosed him with ureteral cancer and performed left nephroureterectomy. Microscopic examination demonstrated adenocarcinoma located in ureteral and pelvic wall, especially in blood vessels, with intact mucosa and similar to adenocarcinoma of colon cancer. Therefore metastatic upper urinary tract tumor was suspected. Barium enema and positron emission tomography-CT demonstrated sigmoid colon cancer. Biopsy specimen of colon cancer demonstrated adenocarcinoma, which was consistent with the ureteral tumor. Finally we diagnosed him with metastatic upper urinary tract tumor of sigmoid colon cancer.