Abstract
A 67-year-old man was referred for evaluation of bilateral external auditory canal cholesteatomas. Five months earlier, he had developed right-sided otorrhea and severe otalgia requiring a visit to the emergency department. In the months that followed, he had experienced four or five similar episodes, including one with frankly bloody otorrhea. He complained of bilateral hearing loss, slightly worse on the left side. He reported occasional disequilibrium and sometimes vertigo with certain motions, such as rising from a chair or rolling over in bed. He reported a distant history of foreign body (cotton) impaction in the left ear, without trauma to the tympanic membrane. His otologic history was otherwise unremarkable. His medical history was significant for chronic kidney disease dependent on hemodialysis.
Otoscopic examination of the right ear revealed a cholesteatoma with significant erosion of the canal floor and some degree of bone exposure. The tympanic membrane was intact and showed pulsatile movement, and there appeared to be fluid within the middle ear space. Examination of the left ear revealed a canal cholesteatoma extending through a well-circumscribed defect of the posterior bony canal wall just lateral to the tympanic membrane. Purulent fluid and squamous debris were noted within the mastoid through the mouth of the cholesteatoma (figure 1). A Weber test lateralized to the right, and a Rinne test was negative bilaterally. The remainder of the patient's head and neck and cranial nerve examination was within normal limits.
Otoscopic image of the left ear shows a canal cholesteatoma causing destruction of the posterior bony canal wall but sparing the tympanic membrane.
Audiometric testing on the right side demonstrated a mild, then sharply downsloping to profound, high-frequency sensorineural hearing loss (SNHL) with 80% discrimination. On the left, there was a profound, flat SNHL with no measurable discrimination.
High-resolution computed tomography (CT) demonstrated extensive pneumatization of both temporal bones. On the right, a soft-tissue mass was seen eroding the canal floor and extending toward the temporomandibular joint. On the left, there was a broad defect of the posterior bony canal wall leading to a confluent area of mastoid air cells lateral to the Koerner septum (figure 2). There was also nondependent soft tissue abutting the posterior middle ear and extending into the epitympanum, with marked erosion of the incus body. Given our patient's greater symptoms and worse hearing on the left, he was scheduled for a left-sided canal-wall-up mastoidectomy and posterior atticotomy with tragal cartilage reconstruction of the posterior bony canal wall.
Axial CT of the left temporal bone demonstrates destruction of the posterior bony canal wall (arrow) with invasion of the adjacent mastoid air cells (arrowheads).
External auditory canal cholesteatomas are rare and estimated to be present in 1 of every 1,000 patients presenting to otologists. 1 They may be classified as idiopathic or secondarily acquired, most commonly occurring in postoperative or post-traumatic settings. 2 Surgical treatment is usually curative, and the choice of operation depends on the extent of the disease. With extension into the mastoid, a mastoidectomy is required to remove all of the disease. 3 The choice of canal-wall-up versus canal-wall-down mastoidectomy depends on the exposure required to be able to adequately assess and remove the full extent of the disease. 3 Reconstruction of the posterior wall has been accomplished using a variety of materials, including cartilage 2 and temporalis fascia. 3 Given our patient's extensive pneumatization, relatively discrete focal posterior wall defect, and intact tympanic membrane, we chose to reconstruct the posterior wall with tragal cartilage.