Langerhans' cells histiocytosis.

Langerhans cell histiocytosis (LCH) is a rare disorder of unknown cause, characterized by the proliferation of histiocytic cells in various tissues and organs. The role of the otolaryngologist is important in the early and accurate evaluation, staging and diagnosis of LCH, because it may mimic more common diseases such as otitis externa and acute mastoiditis. We discuss a case report of bilateral mastoid involvement in a child with a history of otalgia unresponsive to medical therapy.