Skin findings in ECD. (A) Periorbital xanthelasmas in a patient with ECD. Note mild exophthalmos secondary to retro-orbital mass. (B) Upper lid xanthelasmas are apparent when the patient’s eyes are closed. (C) Skin lesions containing foamy macrophages negative for S-100 protein but with activating ALK gene fusion. (D) Skin lesion positive for BRAF V600E mutation. (E) Foamy macrophages in skin lesion. Inset shows lipid-laden macrophages interspersed with inflammatory cells (original magnification ×20; hematoxylin and eosin stain).