Primary cutaneous small/medium CD4+ T-Cell lymphoma occurring during treatment with vemurafenib for advanced melanoma.

The discovery of BRAF mutations in 40%-60% of melanomas led to the development of BRAF inhibitors, which exhibit objective response in over 50% of patients. However, up to 98% of the patients develop at least 1 side effect. We report for the first time a patient with metastatic melanoma harboring BRAF V600E mutation that develops a primary, cutaneous small/medium CD4 T-cell lymphoma secondarily to the treatment with vemurafenib. A 54-year-old man with a history of metastatic melanoma treated with the oral BRAF inhibitor vemurafenib presents, 4 months after the initiation of the treatment, with multiple, nodular firm nonulcerated lesions on his back. Two skin biopsies from the lesions revealed a primary, cutaneous small/medium CD4 T-cell lymphoma.The extensive use of recently approved mutation-specific RAF inhibitors seems to be speeding up the emergence of unknown nonpreventable toxicities of these agents. Our patient developed a primary, cutaneous small/medium CD4 T-cell lymphoma, which presented 4 months after the commencement of vemurafenib. Although no treatment interruption is normally required, a close monitoring of the patients with advanced melanomas treated with vemurafenib seems imperative to optimize the management strategies.