Other Iatrogenic Immunodeficiency-associated Lymphoproliferative Disorder Presenting as Primary Bone Lymphoma in a Patient with Rheumatoid Arthritis

Small intestinal follicular lymphoma induced by methotrexate: a case report

Background

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a rare but critical complication that develops in patients treated with MTX. Although MTX-LPD has been recently reported, the incidence of follicular lymphoma in the intestine is very low.

Case presentation

A 73-year-old woman who had been receiving MTX for over 10 years visited our hospital complaining of postprandial abdominal pain and nausea. Upper and lower digestive tract endoscopies did not show any abnormal findings. A patency capsule was stagnated at the proximal part of the ileum with a mild dilation on the oral side. An oral balloon endoscopy revealed shallow ulcerative lesions in the jejunum. She was diagnosed with MTX-LPD based on histopathological findings. The symptoms did not improve with the discontinuation of MTX, and the patient required partial resection of the small intestine. The test result for Epstein-Barr virus-encoded small RNA was negative. She was diagnosed with follicular lymphoma based on the histology findings of a surgical specimen. Postoperative positron emission tomography-computed tomography and bone marrow aspiration did not show any findings of lymphoma. On follow-up, no recurrence was noted four years after the surgery.

Conclusions

Herein, we report the first case of follicular lymphoma that occurred in the small intestine, negative for Epstein-Barr virus-encoded small RNA. If intestinal symptoms occur during MTX administration, it is important to directly observe by endoscopy and perform histological examination.

Lymphoproliferative disorder in an elderly rheumatoid arthritis patient after longterm oral methotrexate administration: A case report

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is frequently reported in the literature; however, its pathophysiology has not been fully elucidated to date. We herein describe a case of MTX-LPD that occurred after long-term treatment with oral MTX in a 67-year-old Japanese woman with rheumatoid arthritis (RA) who presented with generalized lymphadenopathy of the neck. The patient had been diagnosed with RA 24 years earlier, and had been on oral MTX for 20 years. The patient noticed a mass on her neck, which prompted a visit to our hospital. The mass was confirmed as diffuse large B-cell lymphoma by biopsy. MTX treatment was discontinued, which resulted in a reduction in the size of the mass and improvement of the patient's symptoms. Therefore, clinicians must be aware of MTX-LPD as a differential diagnosis for patients with rheumatological conditions on long-term MTX therapy presenting with signs and symptoms suggestive of lymphoma.