[Ultrastructural study in four cases of cutaneous xanthomas in children (author's transl)].

Three cases are associated with a Reclinghausen disease. Histological findings show typical xanthoma. Electron microscopical study indicates: --numerous intracytoplasmic lipid inclusions of various type (droplets, crystals, concentric lamellar bodies, ceroid granules) in dermal cells (histiocytic foam cells, endothelial cells, Schwann cells, fibroblasts and most cells); --large intranuclear inclusions in some histiocytes containing few lipids droplets; these figures could be compared to a slice of "petrified wood"; their significance is as yet unknown (Liesegang rings?).