Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a recently recognized B-cell lymphoproliferative disorder that is driven by latent EBV infection and causes discrete ulcerations in the oropharynx, gastrointestinal tract, and skin.
A 56-year-old Japanese woman with a 1-month history of swelling in the right side of lower gingiva visited our hospital. The patient had a past medical history of rheumatoid arthritis (RA). She had been given a diagnosis of RA in 1981 and had received standard treatment with methotrexate (MTX) (8 mg/week) for more than 26 years (total dose, greater than 3840 mg). Following initial biopsy and withdrawal of the MTX, the area healed spontaneously over a period of several weeks. The morphological and immunophenotype features were in keeping with an EBV-related lymphoproliferative lesion consistent with EBVMCU. We requested discontinuation of methotrexate, and the lesion decreased and symptoms disappeared in 2 months. There was no evidence of recurrence 25 months after discontinuing methotrexate.
