Salivary gland choristoma of the middle ear. A review.

While head and neck surgeons are accustomed to recognizing malignancies in their practices, developmental lesions are much less often encountered, and as such are not as likely to be included amongst other (more aggressive) differential diagnostic considerations. One such developmental lesion is the choristoma, defined as an architecturally normal arrangement of mature tissues found in a location not normally host to such tissues. Choristomas composed of recognizable salivary gland tissue may be found in a variety of locations including the middle ear. Middle ear salivary choristomas are distinctly unusual lesions and typically manifest as unilateral conductive hearing loss; while both adult and pediatric patients have been diagnosed with middle ear choristomas, most patients have been in the first two decades of life. As these are benign, nonprogressive lesions, treatment has been directed toward complete surgical excision whenever feasible, and biopsy for diagnosis with subsequent observation in the case of those lesions which are difficult to remove without endangering the facial nerve. There have been rare instances in which choristomas have been linked to the subsequent development of neoplasms, but in the main choristomas are regarded as self-limited developmental heterotopias.