Diverticular perforation with exclusive local invasion in cytomegalovirus infection during ganciclovir treatment: an autopsy case report.

Introduction and importance: Cytomegalovirus (CMV) can cause severe colitis in immunocompromised patients. While its morphological manifestations vary, diverticular perforation is rare, with most lesions remaining intact. We report a rare case of CMV-related diverticular perforation in an elderly woman undergoing ganciclovir treatment. Despite intensive care, she died during hospitalization. Autopsy findings showed a congested small intestine without significant erosion or ulceration. Clinical presentation: An 83-year-old woman with prolonged methotrexate and steroid use for rheumatoid arthritis was referred to our hospital due to hypotension, hypoxemia, and altered mental status following bloody stools. Endoscopy revealed a rectal hemorrhage. After hemostasis, the patient developed septic shock and diarrhea, raising suspicion of CMV colitis, which was confirmed by CMV antigenemia. Despite treatment with ganciclovir, the patient developed a diverticular perforation. Histological examination of the surgical specimen revealed localized infiltration of CMV-infected cells in the granulation tissue at the perforation site, without other inflammatory changes. The patient died from liver failure on the 28th day of hospitalization. Clinical discussion: CMV colitis is reported in patients with autoimmune diseases and, in severe cases, can lead to gastrointestinal perforation. In this case, CMV infection caused diverticular perforation; however, autopsy revealed no significant inflammatory changes throughout the gastrointestinal tract. This suggests a highly localized CMV invasion, a rare clinical presentation. Conclusion: Ganciclovir failed to prevent focal bowel perforation, although it may have eradicated CMV within rectal ulcer lesions. Clinicians should be aware that CMV infection can present as diverticular perforation due to localized invasion, even during antiviral therapy.