[Primary adenocarcinoma of renal pelvis and ureter suspected as metastatic tumor: a case report].

A 58-year-old man, who had undergone sigmoidectomy for sigmoid colon adenocarcinoma 3 years earlier, was referred to our clinic because of left ureteral tumor incidentally found by computed tomography (CT). Under the diagnosis of left ureteral carcinoma, retroperitoneoscopic left nephroureterectomy was performed. Pathological examination revealed adenocarcinoma of the left renal pelvis and ureter. Subtype of the adenocarcinoma was 'enteric type'. Five months later, urine cytology was positive and multiple non-papillary tumors were found on cystoscopy. By the transurethral resection of the tumors, bladder tumors appeared to be adenocarcinoma. Carefully considering the pathological findings and clinical course, we concluded that the tumor was not metastatic but primary adenocarcinoma followed by intravesical recurrence.