[Histiocytosis X of temporal bone in a 5 year old boy].

Histiocytosis X or Langerhans cell histiocytosis (LCH) is a disease including three less distinctive and overlapping conditions called eosinophilic granuloma (EG), Hand-Schüller-Christian (HSC) disease and Letterer-Siwe (LS) disease. A high index of suspicion is required to diagnose histiocytosis, especially when an ear disease is refractory to medical treatment. The authors present a case report of histiocytosis X in a 5-year-old boy with ear involvement. Bone destruction involved temporal bone and zygomatic process. The role of imaging diagnosis in evaluation of lesion extent with special consideration of CT is presented.