The occurrence of cytomegalovirus colitis is well known in immunosuppressed patients, such as neoplastic patients following chemotherapy, although its exact etiology remains unclear.
We present a case of cytomegalovirus colitis occurring in a 77-year-old man with vomiting and diarrhea 2 weeks after initial systemic chemotherapy consisting of 5-fluorouracil, leucovorin and irinotecan for a recurrent colorectal cancer. Initial colonoscopy revealed multiple punched-out ulcers in the transverse colon and the diagnosis of cytomegalovirus was based on positive cytomegalovirus antigen detected by indirect enzyme antibody method, although immunohistological examination of tissues biopsied at colonoscopy was negative. The symptoms ceased under ganciclovir and octreotide treatment, and the patient recovered gradually.
The most probable cause of the cytomegalovirus colitis in this case was impaired immunity following chemotherapy. Cytomegalovirus infection should be included in the differential diagnosis of gastrointestinal disease in colorectal cancer patients after chemotherapy and, when suspected, the clinician should pursue appropriate diagnostic interventions including colonoscopy.