A Case of Ileal Perforation due to Cytomegalovirus Enteritis that was Difficult to Differentiate from Perforated Appendicitis

Abstract

The patient was a 62-year-old male, who presented with a one-week history of fever while receiving chemotherapy for multiple myeloma. Abdominal CT demonstrated an abscess around the ileocecal area and rupture of the appendix. An emergency laparotomy was performed with the suspected diagnosis of perforated appendicitis. The appendix was enclosed in the abscess on the dorsal side of the ileocecum, and ileocecal resection was performed. Postoperatively, the low-grade fever and diarrhea persisted. Serum test for cytomegalovirus (CMV) antigen prior to surgery came back positive. Based on this result, the patient was finally diagnosed as having CMV enteritis and started on treatment with valganciclovir. Both fever and diarrhea improved within a few days after the start of valganciclovir treatment. Histopathologically, a deep ulcer perforating the terminal ileum, with abscess formation was noted. CMV-infected cells were identified in the tissue around the ulcer. From the clinical course and histopathological findings, we made the final diagnosis of CMV enteritis with perforation of the ileum and secondary rupture of the appendix. In this case, it was difficult to differentiate the actual diagnosis from primary perforated appendicitis prior to the surgery. In regard to gastrointestinal perforation in immunocompromised patients, it is necessary to bear in mind the possibility of CMV enteritis, even though it is an extremely rarely encountered condition. Prompt serological testing for CMV antigenemia is useful for early diagnosis and treatment.