P11.08 * CENTRAL NERVOUS SYSTEM LYMPHOMA IN A PATIENT WITH MYCOSIS FUNGOIDES

Abstract

Mycosis fungoides (MF), the most common malignant T-cell lymphoma of the skin with an annual incidence of 4.2 cases per million in the United States, usually evolves slowly over many years. Extracutaneous manifestations of MF are observed in 50-75% of cases, typically occurring in patients with advanced infiltration of other organs. The incidence of central nervous system (CNS) involvement in MF was reported to be 14% in autopsy series and less than 1.6% in clinical cohorts particularly in patients with large-cell transformation of MF. A 67-year-old woman was diagnosed with plaque stage MF in 1990 after having developed disseminated, well demarcated, erythematous macules and plaques on the trunk. The patient reported that psoriasiform skin lesions had been present over the past 35 years. Treatment consisted of topical corticosteroids, systemic psoralen plus ultraviolet A, acitretin and interferon, resulting in a complete remission since 2007, without further treatment. In April 2013, the patient presented with a 2-month history of cognitive deficits and bifrontal headache, followed by rapidly decreasing visual acuity with central and peripheral visual field defects. Magnetic resonance imaging (MRI) showed thickening of the optic chiasm and both optic nerves with homogeneous contrast medium enhancement and space-occupying effect on the hypothalamus. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis of 107 cells/µl, no lymphoma cells were detected, CSF protein was elevated (116 mg/dl), glucose and lactate were normal. A subsequent brain biopsy confirmed the diagnosis of a diffuse large-cell lymphoma of the B-cell type. Despite preoperatively started dexamethasone treatment the patient experienced severe visual loss. Following 4 cycles of chemotherapy containing high-dose methotrexate and cytarabine according to the IELSG protocol and 2 cycles of methotrexate monotherapy from May until October 2013, clinical examination showed marked visual improvement, consistent with almost complete resolution of the MRI abnormalities. Due to pituitary gland insufficiency the patient needs further hormone replacement therapy. This case illustrates the importance of considering CNS lymphoma in the context of MF, even after long-term remission of the disease limited to the skin. To the best of our knowledge, this is the first description of a primary CNS B-cell lymphoma secondary to MF.