Eosinophilic granuloma of temporal bone

Eosinophilic granuloma is an uncommon granulomatous disease which can affect the temporal bone. Also known as Langerhans cell histiocytosis, the lesion is characterized by uncontrolled proliferation of Langerhans cells. Although initially silent, the disease may erode the mastoid cortex, destroy the tegmen, and extend into the cranial vault, as well as erode the semicircular canals or cochlea. These lesions almost always become infected and can be confused with chronic otomastoiditis. Equally important, temporal bone involvement may represent only one manifestation of a multifocal disease. This report describes a case of 40-year-old male with eosinophilic granuloma involving the right temporal bone extending into midbrain region causing focal compression and displacement of part of the temporal lobe.