Abstract

Glial choristoma is defined as a mass that is composed of mature, normal brain tissue, isolated from the cranial cavity or spinal canal. The involvement of an extracranial non-midline location, especially the middle ear or mastoid region, is quite exceptional. We report here on a case of glial choristoma of the middle ear in a 2-year-old boy. He presented with otalgia and otorrhea that had lasted for 6 months, and radiological studies revealed a mass-like lesion with soft tissue density in the middle ear cavity. The patient underwent simple mastoidectomy and tympanoplasty. Histologically, the mass was composed of disorganized but mature, normal glial tissue with immunoreactivity for glial fibrillary acidic protein. The patient had no previous history of head trauma or surgery, and no evidence of central nervous system connection was noted on the radiological or operative findings. This mass was regarded as a primary glial heterotopia rather than an acquired encephalocele.

• Keywords: Choristoma;Glia;Middle ear;