Sigmoid colon carcinoma metastatic to prostate.

Although primary prostatic carcinoma is very common, prostatic metastasis is unusual. We describe a unique example of prostatic metastasis from noncontiguous colon cancer, after presumed curative resection of the primary tumor. Potential mechanisms of metastasis are examined in the context of clinical and histopathologic evidence. A possible role is proposed for early transrectal ultrasound examination in diagnosis of patients with unexplained urologic symptoms after resection of colorectal cancer.