Abstract
We present a case illustrating the workup and diagnosis of peritoneal sarcomatous mesothelioma as an unusual etiology of intestinal obstruction and high-protein ascites in an otherwise healthy man. This rare disorder is diagnosed based on immunohistochemistry, which is necessary to differentiate it from other rare sarcomatous carcinomas. In many cases, localized disease can be treated to cure with surgery and intraperitoneal chemotherapy. Advanced disease is often treated for palliation of symptoms.