Primary Central Nervous System Lymphoma in a Patient on Adalimumab Therapy for Chronic Plaque Psoriasis

Adalimumab (Humira) is a recombinant human monoclonal antibody against tumor necrosis factor alpha, which works by blocking the interaction of tumor necrosis factor alpha 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 nonmelanoma skin cancer and non-central nervous system lymphomas, have been reported with use of this drug; however, there have been no reports of central nervous system lymphomas.

A 43-year-old man presented for evaluation following recent speech difficulty and a generalized tonic-clonic seizure. His medical history was significant for plaque psoriasis, for which he had been receiving treatment with adalimumab for 4 months. Magnetic resonance imaging scan of the brain with contrast agent showed a well-defined rounded enhancing lesion in the left temporal lobe with circumferential vasogenic edema. Mass effect was noted. Computed tomography scan of the 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 adalimumab was discontinued. Following combination therapy with high-dose methotrexate and rituximab along with 20 sessions of cranial radiation therapy, the patient was disease-free at 14-month follow-up.

We report the first case to our knowledge showing a possible association of central nervous lymphoma and adalimumab.