September 2000: 15 year old girl with intracranial lesion.

The September COM: We reported the case of a 15 year old white girl with solitary brain cortical lesion clinically mimicking meningioma. Microscopic examination revealed histiocytic lesion with foamy and giant cells predominately of Touton type. Subsequent clinical examination did not reveal any similar lesion in the skin or in other location. Expression of S-100 protein in histiocytes is unusual finding, but has been reported recently in juvenile xanthogranulomas (JXG). The only specific ultra-structural finding differing JXG from histiocytic neoplasm of Langerhans' cells histiocytosis type seems to be Birbeck granules.