Colon ulceration in lethal cytomegalovirus infection.

Six renal transplant recipients with severe cytomegalovirus (CMV) infection developed colonic ulceration and lower gastrointestinal bleeding. All patients died between four and 84 days following onset of bleeding. Four patients required colon resection to control blood loss. In the remaining two cases, there was complete autopsy examination with thorough tissue sampling of the colon. In addition to routine light microscopic examination, all cases were studied with an immunoperoxidase technic for identification of CMV. Electron microscopic examination of the colon was performed on two cases. In this select group of patents, CMV plays an active role in damaging colonic mucosa, primarily as a result of CMC vasculitis. Clinical and pathologic features of our cases are compared to published reports of CMV infection of the colon.