Mucocutaneous ulcer positive for Epstein–Barr virus, misdiagnosed as a small bowel adenocarcinoma: A case report

BACKGROUND: Epstein–Barr virus (EBV)-positive mucocutaneous ulcers (MCUs) are an uncommon disorder characterized by ulcerative lesions in the skin, oral cavity or gastrointestinal tract in patients with iatrogenic or aging-induced immunosuppression. The nonspecific lesions are difficult to differentiate from small bowel adenocarcinomas. We present the case of a 69-year-old woman who was initially misdiagnosed with a small bowel adenocarcinoma but was later surgically diagnosed with and treated for EBV-MCU. Through this case, we aim to emphasize the importance of accurately distinguishing between the two conditions. CASE SUMMARY: The patient presented with an incidental finding of a small bowel tumor during computed tomography (CT) examination performed for hematuria. The CT scan showed irregular thickening of the distal ileum, which was suggestive of a malignant small bowel tumor. An exploratory laparotomy revealed an 8-cm mass in the distal ileum; thus, a segment of the small intestine, including the mass, was resected. Histopathological analysis revealed an ulceroinfiltrative mass-like lesion with luminal narrowing, marked inflammatory cell infiltration, and large atypical lymphoid cells (positive for EBV-encoded small RNA). A final diagnosis of an EBV-MCU was established. The postoperative course was uneventful, and the patient was discharged on postoperative day 7. The patient remained recurrence-free until 12 mo after surgery. CONCLUSION: This case highlights the diagnostic challenges for EBV-MCUs and emphasizes the importance of comprehensive evaluation and accurate histopathological analysis.