Multisystemic and Multiresistant Langerhans Cell Histiocytosis: A Case Treated With BRAF Inhibitor.

Langerhans cell histiocytosis (LCH) is a rare proliferative disease with a wide spectrum of clinical presentations and, as a consequence, the treatment choice is unclear. Recently, detection of the BRAF V600E mutation changed the perspective of this disease, suggesting a possible use for BRAF inhibitors in its treatment. Herein, a case is presented of a patient with LCH undergoing treatment with vemurafenib after several lines of therapy. After 4 months of vemurafenib treatment, skin lesions associated with cranial involvement were reduced in size at physical evaluation and nuclear imaging assessment showed a very good partial response, with the resolution of multiple lesions. Based on this very good partial response and because the patient tolerated treatment well, the patient was able to continue treatment with vemurafenib until disease progression nearly 10 months later. This approach should be considered for patients with severe and multiresistant LCH with a BRAF mutation. However, more studies are needed to evaluate the efficacy and duration of response in a larger patient population.