Stenosing colonic adenocarcinoma in a female rhesus monkey

Laparoscopic surgery was performed on a 16 year-old female rhesus monkey presenting with chronic lethargy and inappetence. The procedure revealed a "napkin-ring" stricture located in the ascending large colon. Histologic evaluation of the colonic lesion exhibited large numbers of irregular acini lined by a single layer of well-differentiated neoplastic epithelial cells. Based on the gross and histopathologic findings a diagnosis of adenocarcinoma of the proximal colon was made.