Multiple xanthogranulomas in an adult patient: clinical, dermoscopic, reflectance confocal microscopy and histopathological features.

A case of multiple xanthogranulomas located bilaterally on arms, armpits, legs, trunk, abdomen, scalp, neck and plantar surfaces in a 25-year-old man is reported. The patient was evaluated by polarised light dermoscopy and reflectance confocal microscopy (RCM) that showed peculiar aspects. In particular, dermoscopy showed a homogeneous orange-yellowish hue that is related to the histopathological presence of foamy histiocytes and Touton giant cells; the last typically appeared at RCM as peculiar giant cells surrounded by highly refractive ring due to the cytoplasm rich of lipids. Laboratory investigations, including routine haematological examination, liver and renal function tests, serum lipid and sugar levels were normal. The patient started isotretinoin 20 mg once daily. After 6 months, some lesions flattened, leading to yellowish or hyperpigmented macules, but new lesions raised up.