Cytomegalovirus colitis masquerading as rectal malignancy in an immunocompetent patient.

Gastrointestinal tract (GIT) involvement by cytomegalovirus (CMV) infection is well-recognized in immunosuppressed patients but is uncommon in immunocompetent hosts. The colon and esophagus are the most frequently affected sites with punched out ulcers being the characteristic mucosal lesion. CMV-induced pseudotumor is an exceptionally rare presentation, especially in immunocompetent hosts. A 76-year-old immunocompetent female presented with abdominal pain and constipation. Colonoscopy revealed an ulcerated polypoidal tumor-like mass in the anorectal region. Biopsy of the lesion showed large basophilic intranuclear inclusions which were positive for CMV on immunohistochemical staining. The patient responded to 2 weeks of antiviral therapy with complete resolution of the mass. Although rare, pseudotumors associated with CMV infection should be considered in the differential diagnosis of tumorous lesions of the GIT.