Cytomegalovirus Colitis Mimicking Rectal Tumour in an Undiagnosed HIV Patient.

Introduction: Cytomegalovirus (CMV) is the most common opportunistic agent in HIV-infected patients. It can affect the entire gastrointestinal tract, but frequently involves the oesophagus and the colon.

Case Report: We report the case of a 70-year-old female, ultimately diagnosed with HIV infection, whose inaugural clinical manifestation was CMV colitis with endoscopic findings resembling a rectal tumour in which initial histological evaluation was not able to provide a proper diagnosis.

Discussion/conclusion: Since clinical presentation is variable and histopathological yield without immunohistochemical analysis is poor, recognizing CMV infection in the absence of known risk factors may be difficult. It is crucial to consider this entity with suspicious lesions or when initial evaluation, either clinical or histopathological, is inconclusive, thus avoiding potentially debilitating and superfluous treatment or life-threatening complications.