xanthomatous infiltration of tissues by CD68-positive and CD1a-/CD100-negative foamy
histiocytes. In childhood, ECD is exceptionally rare, and only a dozen cases have been
published so far. The cooccurence of Langerhans cell histiocytosis (LCH) and ECD is even
rarer. Here, we report a 2-year-old boy, the youngest patient in the literature so far, who was
diagnosed with concomitant BRAF mutation-positive LCH and ECD. In his case …