Prostate cancer metastasizing to the small bowel

Although prostate cancer is one of the most commonly encountered malignancies in clinical practice, it is very unusual for prostate cancer to metastasize to the small bowel. Our search of the literature found no such cases published from 1966 to the present. We report the case of a 69-year-old man who presented for evaluation of anasarca and anorexia. He had a history of prostate cancer diagnosed 9 years before and had undergone a radical prostatectomy with subsequent radiotherapy for positive tumor margins. He developed anasarca 2 years before presentation to us. His serum albumin ranged between 1.5 and 2.5 g/dL. Upper endoscopy was performed for possible protein-losing enteropathy and the appearance of gastric and duodenal mucosa was found to be normal. Random small bowel biopsies revealed submucosal infiltrating adenocarcinoma with positive prostate-specific antigen stains consistent with the diagnosis of prostate cancer metastatic to the small bowel. This is a rare presentation of metastatic prostate cancer. Even though prostate cancer is the most commonly diagnosed cancer in American men, antemortem diagnosis of small bowel metastasis has not been reported. In patients with unexplained anasarca, especially with a history of malignancy, an upper endoscopy with small bowel biopsy may be useful in establishing the diagnosis.