[Early onset of methotrexate-associated lymphoproliferative disorder mimicking Hodgkin's lymphoma].

Long-term methotrexate (MTX) treatment is known to cause MTX-associated lymphoproliferative disorder (MTX-LPD). A 58-year-old woman with psoriasis vulgaris and pityriasis rubra pilaris was treated with a combination of MTX and ustekinumab for 4 months when she developed generalized lymphadenopathy. The initial histopathological analysis indicated Hodgkin's lymphoma; however, assessing the patient's clinical history revealed the diagnosis of MTX-LPD. To our knowledge, this is the first case of a MTX-LPD after only 4 months of treatment.