Acquired cholesteatoma presenting as a large pars squamosa temporal bone mass

Educational Objective: At the conclusion of this presentation, the participants should be able to discuss the differential diagnosis of a pars squamosa temporal bone mass, discuss unusual locations in which cholesteatoma may appear, and explain the need for long term followup in canal wall down mastoidectomy patients. Objectives: To present a case of an acquired cholesteatoma presenting as a large lateral pars squamosa temporal bone mass and review the literature on cholesteatoma presenting in unusual locations. Study Design: Case report and review of the literature. Methods: While congenital cholesteatomas have been reported to arise in atypical locations such as the maxillary sinus and occipitoparietotemporal junction, there have been very few reports of acquired cholesteatomas arising in unusual locations. A 16 year old female with an acquired cholesteatoma presenting as a large lateral squamous temporal bone mass with intracranial extension nine years after canal wall down (CWD) mastoidectomy and six years after revision surgery is presented. Her management and followup are discussed and a review of the literature for atypical locations of cholesteatoma is presented. Results: Review of the English literature revealed only a single case of acquired cholesteatoma within the squamous temporal bone. Our patient underwent successful excision of the mass through a lateral approach, confirming the diagnosis. Conclusions: Acquired cholesteatoma typically arises in the middle ear and mastoid. Rarely, it can present in atypical locations. The consequences of undiagnosed, untreated cholesteatoma can be significant. This case highlights the need for routine long term surveillance in children with CWD mastoidectomy cavities.