[Atrophic involution of juvenile xanthogranulomas]

We report an unusual atrophic involution of juvenile xanthogranulomas.

A newborn boy presented with 5 papular, nodular and necrotic lesions located on the upper part of the body. The diameter of the lesions ranged between 1 and 3 cm. Light microscopy showed an infiltrate with foamy and Touton cells. Langerhans' cell histiocytosis was eliminated because none of these cells showed reactivity for S100 protein and CD1a. At the age of 8 years, all the lesions had spontaneously regressed leaving unusual atrophic scars that had the same size as the active lesions.

We compared the clinical, histological and evolution data of our patient with 251 published cases. The most significant clinical feature of juvenile xanthogranuloma is the spontaneous involution without any trace. However, hyperpigmentation, anetoderma or atrophy may occur. Atrophy is not frequent and can result from 2 mechanisms. Inflammation of the hypodermic tissue, which becomes atrophic and atrophy that may also result from collagen remodeling anomalies during the scarring process.