Primary CNS lymphoma in a patient on Adalimumab (Humira) therapy for chronic plaque psoriasis.

Adalimumab (Humira) is a recombinant human monoclonal antibody against tumor necrosis factor alpha (TNF- α), which works by blocking the interaction of TNF- α with its cell-surface receptors, thereby limiting the progression of inflammatory pathways. Its use is approved for several autoimmune conditions including chronic plaque psoriasis for which it has been prescribed as a first-line biologic treatment. Increased risks of malignancy, particularly non-melanoma skin cancer and non-CNS lymphomas have been reported with use of this drug, however, there have been no reports of CNS lymphomas.Here, we report the case of a 43-year old male who presented for evaluation following recent speech difficulty and a generalized tonic-clonic seizure. He has a medical history significant for plaque psoriasis on treatment with adalimumab for 4 months. An MRI brain with contrast showed a well defined rounded enhancing lesion in the left temporal lobe with circumferential vasogenic edema. There was mass effect noted. A CT chest, abdomen and pelvis was unremarkable. He underwent excisional biopsy and the preliminary intraoperative pathology report revealed a diagnosis of high-grade lymphoma. Subsequent analysis of morphology and immunophenotyping was consistent with primary diffuse large B-cell lymphoma of the central nervous system. Use of Humira was discontinued. Following combination therapy with high dose methotrexate and rituximab along with twenty sessions of cranial radiation therapy, the patient is disease free at fourteen months follow up since surgery.This illustrates the first case of a possible association of central nervous lymphoma and adalimumab.