Treatment of Methotrexate-Associated Lymphoproliferative Disorder With Biological Therapies.

Lymphoproliferative disorders may arise as a complication of immunosuppressant medications, such as methotrexate. This case report describes a patient who developed a rare subtype of methotrexate-associated lymphoproliferative disorder. His disease initially responded well to the withdrawal of methotrexate. However, several months after diagnosis, surveillance testing revealed progressive lymphadenopathy. Owing to his multiple comorbidities and resultant poor baseline functional status, he was not a candidate for cytotoxic chemotherapy. Based on key histopathological characteristics of his rare disorder, his care team devised an alternative therapy, consisting of rituximab and brentuximab, a unique protocol that is not well-described in the lymphoma literature. The patient achieved a brief but complete remission from this therapy.