Distant Ureteral Metastasis from Colon Adenocarcinoma: Report of a Case and Review of the Literature

Carcinomas arising from organs neighbouring the ureter can directly infiltrate the ureter. Distant ureteral metastasis from colon adenocarcinoma is extremely rare and usually an incidental finding in performed autopsies. We report a case of a right ureteral metastasis in a 65-year-old Caucasian male with a history of rectal cancer for which he had been treated 4 years before. He presented with asymptomatic moderate right hydronephrosis. The patient underwent a right nephroureterectomy. Histology of the ureter revealed transmural adenocarcinoma with infiltration of the mucosa. Infiltration of the muscular coat of the bladder was found 2 years later. Thus, cystectomy and left ureterocutaneostomy were performed. The patient died 6 months later due to toxic megacolon during chemotherapy. The differential diagnosis of ureteral adenocarcinoma, especially in patients with previous history of colon adenocarcinoma, should include the possibility of distant metastasis from the primary colonic tumor. 1. Introduction Distant metastases to the ureter may occur through lymphatic and/or blood vessels excluding ureteral involvement by direct extension [1–3]. These metastases have been reported more commonly arising from stomach, breast, lung, cervix, prostate, pancreas, and lymphoma [2–6]. Distant ureteral metastases from colon adenocarcinoma are considered to be very rare [2–10]. We present a case of this condition and review the English language literature. 2. Case Report In November 2005 a 61-year-old male patient underwent rectosigmoidectomy for nonmetastatic rectal cancer (grade II, stage T3N1MO), which was followed by chemotherapy (oxaliplatin and capecitabine) and radiotherapy. He had no signs of relapse during the follow-up. In May 2009 an asymptomatic moderate right hydronephrosis in follow-up computed tomography (CT) scan was revealed. The ureteropyelogram (Figure 1) showed a 1.5？cm filling defect in the lower right ureter. Ureteroscopy revealed a papillary lesion. Urine cytology showed malignant cells strongly suspicious for adenocarcinoma which correlated with the biopsy findings where immunohistochemistry demonstrated carcinoma with glandular differentiation and positivity for cytokeratin (CK) 20, fully compatible with a metastatic colonic type adenocarcinoma. The patient was fully evaluated with colonoscopy and CT (Figure 2) with no signs of local or distant relapse. Figure 1: Ureteropyelogram revealing an obstruction of the lower right ureter, local ureteral dilatation, and intraluminal filling defect. Figure 2: Computed tomography of the pelvis showing