Metastatic Prostate Cancer Presenting as a Rectal Polyp: A Rare Occurrence

Abstract

The prostate is anatomically located anterior to the rectum. Due to this proximity, locally advanced tumors of the prostate can invade the rectal tissue; likewise, colorectal cancers can invade the prostate gland; This presents mainly as an invasive mass with an identifiable primary and is rarely an isolated lesion. Prostate cancer rarely affects the gastrointestinal tract. Few cases of prostate cancer metastatic to the gastrointestinal tract have been reported in patients with a known prostate cancer history. Initial diagnosis of prostate cancer diagnosed from a colonic polyp is rare. We report a case of metastatic prostate cancer first diagnosed from a rectal polyp. Our patient is a 76-year-old man who initially presented with fatigue and 20 pounds weight loss in five months. The patient never had a colonoscopy before the presentation. A colonoscopy was done, which showed multiple colonic polyps and a pathology report of metastatic prostate cancer from a 12 mm rectal polyp.

Rectal Invasion by Metastatic Prostat Cancer 15 Years after Prostate Cancer Surgery

“…In rectal metastasis due to prostate cancer, sometimes rectal bleeding, rectal discomfort or bowel obstruction may be present [7,8]. Our patient had chronic constipation that did not respond to drug therapy, and colonoscopy due to chronic constipation revealed thickening and irregularity in the rectal wall.…”

“…In the literature, rectal metastases due to prostate cancer have been rarely reported. In some literature, polypolypoid formation has presented as a polypoid mass or intestinal obstruction [8]. The possibility of metastasis should be considered in a patient with prostate cancer presenting with the complaint of rectal bleeding [9,10].…”