LCH was defined as a neoplastic lesion of myeloid origin following the discovery of the BRAF V600E mutation, a classification that persisted until 2010.1 The annual incidence of LCH is 0.5 to 5.4 cases per 100,000 individuals in China, with a predominance in males. Here, BRAF is linked to Langerhans cell histiocytosis.