Solitary juvenile xanthogranuloma with tibial involvement: a case report.

Juvenile xanthogranuloma (JXG) is a rare disease that is part of a spectrum of histiocytic dendritic cell disorders. Most patients present with a solitary cutaneous lesion; however, others present with extracutaneous manifestations or even with systemic involvement. We present the first report of an 11-month-old girl in whom was diagnosed a unifocal extracutaneous JXG involving the tibia. Histological and immunohistochemical staining results are presented. A review of the literature on these unusual lesions is conducted, along with discussion of their differential diagnosis and key aspects of the patient's evaluation, management, and pathological diagnosis.