Methotrexate-associated lymphoproliferative disorder: Sequential development of angioimmunoblastic T-cell lymphoma-like lymphoproliferation in the lymph nodes and diffuse large B-cell lymphoma in the skin in the same patient

A 66-year old Japanese woman was diagnosed with polymyalgia rheumatica in October 2012 and was treated with methotrexate (MTX) at a dose of 10mg/week. Swelling of the inguinal lymph nodes appeared in February 2013. Histological examination of the lymph nodes revealed numerous, medium-to-large, atypical mononuclear cells with irregular nuclei (figure 1A). Increased numbers of CD21+ follicular dendritic cells were observed around the high endothelial venules (figure 1B). The neoplastic cells stained [...]