Temporal bone fibrous dysplasia and cholesteatoma leading to the development of a parapharyngeal abscess.

Monostotic fibrous dysplasia of the temporal bone is a rare disease entity that may lead to progressive stenosis of the external auditory canal with resultant trapping of skin and the development of cholesteatoma. The cholesteatoma may extend widely into the temporal bone. Once cholesteatoma occupies the petrous apex, erosion out of the temporal bone can occur superiorly into the middle fossa, posteriorly into the posterior fossa, inferiorly into the neck, and infero-medially into the parapharyngeal space. We present a case in which minimal symptoms were present despite a massive temporal bone fibrous dysplasia and cholesteatoma. Eventually, cholesteatoma eroded into the parapharyngeal space, leading to airway compromise. Late presentation occurred because the otic capsule was spared, there was no external skull deformity and there was slow inferior and medial growth that was well tolerated, until the development of a parapharyngeal space abscess.