Abstract
We report a case of methotrexate-associated lymphoproliferative disorders (MTX-LPD) simultaneously arising in the maxilla and the nasal mucosa of a patient who was receiving bisphosphonate. A 72-year-old woman was referred to our university hospital for suspected medication-related osteonecrosis of the jaw (MRONJ), affecting the maxilla. She had been receiving methotrexates (MTX) to treat rheumatoid arthritis and bisphosphonates to treat osteoporosis. Ulceration in the anterior region of the maxilla accompanied by bone necrosis was observed. A computed tomographic examination revealed edematous swelling of the left nasal mucosa in addition to the maxillary lesion. Histopathological examinations revealed Epstein-Barr virus-positive diffuse large B-cell lymphoma (DLBCL). These findings led to the final diagnosis of MTX-LPD. This is the first report to histopathologically document multiple extranodal MTX-LPD occurring simultaneously in the head and neck regions. After withdrawal of MTX therapy, gradual regression of these lesions was observed. Sixteen weeks after withdrawal, spontaneous complete remission was judged to have been achieved. Subsequently, the osteonecrosis of the maxilla was surgically resected with the patient under general anesthesia. The resected specimen showed chronic osteomyelitis and no malignancy. There has been no evidence of disease recurrence as of 31 months after complete remission of the lesions.
