Solitary giant xanthogranuloma and benign cephalic histiocytosis--variants of juvenile xanthogranuloma.

Sequential biopsies taken from a patient with a solitary giant xanthogranuloma, an exaggerated macronodular (> 5 cm in diameter) variant of juvenile xanthogranuloma, and from a patient with benign cephalic histiocytosis, revealed a characteristic time sequence of histopathological findings. Early stages of the diseases showed a monomorphous infiltrate of mononuclear vacuolated histiocytes positive for KiM1p, HAM56 and factor XIIIa and were characterized by clusters of comma-shaped bodies. This was followed by a polymorphous mixture of various mononuclear and multinucleate histiocytes additionally labelling with KP1 (CD68) and, in occasional cells, for the adherence of peanut agglutinin. A variety of ultrastructural changes were found, including dense and regularly laminated bodies or lipid droplets. Our findings indicate that both entities are variants of a xanthogranulomatous reaction.