Case series of volar juvenile xanthogranuloma: clinical observation of a peripheral rim of hyperkeratosis.

Juvenile xanthogranuloma is a benign histiocytic tumor predominantly occurring in children as yellowish papules on the head and trunk. Presentations on the volar surfaces are rare and may cause diagnostic confusion with pyogenic granuloma, eccrine poroma and digital fibrokeratoma. We report two patients with unusual presentations of solitary juvenile xanthogranuloma on the palm or sole. Both had lesions lacking the classic yellowish color and demonstrating a well-defined, peripheral hyperkeratotic rim. Histopathological evaluation revealed prominent orthokeratosis corresponding to the rim. Additional histological features, including dermal histiocytes and Touton giant cells, were consistent with the diagnosis of juvenile xanthogranuloma. Given the unusual locations and colors of the lesions, we conclude that histopathological evaluation is central to diagnosing volar juvenile xanthogranuloma. We additionally suggest that juvenile xanthogranuloma should be included in the differential diagnoses of volar lesions displaying a peripheral hyperkeratotic rim.