Epstein–Barr virus-positive mucocutaneous ulcer arising in the oral region: A report of three cases and a review

Epstein–Barr virus (EBV)-positive mucocutaneous ulcers (EBVMCUs) are localized mucosal or cutaneous ulcers caused by the proliferation of EBV-infected B cells in patients with immunosuppression. To reach an appropriate diagnosis of EBVMCUs, which have a favorable prognosis distinct from EBV-positive diffuse large B-cell lymphoma (EBV-positive DLBCL) with a poor prognosis, clinicopathological features of cases must be understood. Herein, we describe our experience with three cases of EBVMCUs in the oral cavity and review the literature. In case 1, a 56-year-old woman received methotrexate (MTX) and prednisolone for the treatment of psoriatic arthritis．After teeth extraction, ulcers formed, and bone exposure with necrotic-like tissues was observed. In case 2, a 73-year-old woman received MTX for the treatment of rheumatoid arthritis (RA). After tooth extraction, an ulcer was formed with bone exposure. In case 3, a 60-year-old woman received MTX for the treatment of RA. A well-defined ulcer was found on the left ventral surface of the tongue. All patients showed lesion resolution after MTX withdrawal. Since most EBVMCUs show a favorable prognosis distinct from EBV-positive DLBCL with a poor prognosis, an appropriate diagnosis is necessary.