LAUSR

To the Editor , BRAF inhibitors (BRAFi) vemurafenib and dabrafenib have become the standard of care of metastatic melanoma. Well-described cutaneous side effects include secondary tumors such as squamous cell carcinomas and secondary melanomas and also hand-foot skin reactions, keratosis pilaris-like rashes and acantholytic dyskeratosis.1 Recently, a few cases of vemurafenib-induced panniculits have been published in the literature, including one small series of nine patients.2 We describe two additional cases of panniculits occuring during treatment with vemurafenib and summarize the clinical and histopathological findings of the cases reported to date. The first patient was a 35-year-old woman was diagnosed with a pT3N1a nevoid melanoma on the back. She was treated surgically with a complete excision and lymphadenectomy after a positive sentinel lymph node. After 6 months, she developed pulmonary metastases and underwent chemotherapy with dacarbazine (6 cycles), with no clinical response. BRAF V600E mutation was positive, making the patient eligible for a targeted therapy with a BRAFi. However, vemurafenib treatment was refused by the patient and she was started on ipilimumab. Two months later, tumoral evaluation showed disease progression with widespread pulmonary, bone, hepatic and central nervous system involvement. The patient then agreed to start vemurafenib 960 mg bid. After 6 weeks of treatment, she developed erythematous painful nodules on the extensor surfaces Fig. 1. The biopsy from patient 1 showed a florid lobular neutrophilic panniculitis [hematoxylin and eosin stain (H&E), ×400].