CT appearances of external ear canal cholesteatoma

Osteoma of external auditory canal associated with external auditory canal cholesteatoma and exuberant granulation tissue in mastoid air cell system: a rare association

Osteoma of EAC is a rare tumour. Cholesteatoma of EAC associated with osteoma is consequence of osteoma of EAC. Its incidence is rare and very few cases have been reported in the literature. Its association with exuberant granulation tissue in the mastoid air cell system without extension of Cholesteatoma into middle ear cleft is even rare. This association has been reported for the first time as evident from review of literature.

Computed Tomography Features of External Auditory Canal Cholesteatoma: A Pictorial Review

Computed tomography (CT) is widely used for evaluation of patients with otologic conditions. External auditory canal cholesteatoma (EACC), although rare, demonstrates characteristic CT appearance. Moreover, the accurate extent of involvement cannot be accurately assessed clinically. This pictorial review aims to illustrate the spectrum of CT features of EACC and highlight the key features that are useful for making an accurate diagnosis of this condition. We have also discussed the radiological and clinical differential diagnoses of external auditory canal lesions that can be mistaken for an EACC.

CT Findings in the External Auditory Canal after Transcanal Surgery

BACKGROUND AND PURPOSE

Middle ear surgery is often performed through the external auditory canal, and the CT appearance of the external auditory canal after transcanal middle ear surgery can mimic erosive pathology such as carcinoma, external auditory canal cholesteatoma, or necrotizing external otitis. We reviewed the CT findings in a group of patients following transcanal surgery to highlight this potential pitfall in interpretation.

MATERIALS AND METHODS

Twenty-seven temporal bones in 25 patients with a history of a transcanal approach to the middle ear and available postoperative CT imaging were identified. Images were assessed for changes along or involving the walls of the external auditory canal, including widening, irregularity, bony defects, and soft tissue opacification.

RESULTS

Osseous changes along the floor of the external auditory canal were demonstrated in 25 of 27 (92.6%) temporal bone CT scans. Similar changes were present in the superior and anterior walls of the external auditory canal in 21 and 18 temporal bones, respectively. The anterior wall was the most common site for complete bony defects (10 of 27 temporal bones). The posterior wall was the least often involved, with osseous changes in 15 of 27 temporal bones and bony defects in 3 cases. Soft tissue thickening was seen most commonly along the floor. No patient was found to have a superimposed pathologic process of the external auditory canal.

CONCLUSIONS

CT findings in the external auditory canal after transcanal surgery include thinning, irregularity and/or flattening of the bone, soft tissue thickening, and bony wall defects. Although these changes may be subtle, they may mimic pathology and should be included in the differential diagnosis of osseous abnormality of the external auditory canal.

Cholesteatoma of external auditory canal: a case report

The authors present a case of cholesteatoma of external auditory canal (CEAC) with extensive invasion of mastoid; ossicle chain and tympanic membrane remained intact. The only symptom was chronic otorrhea. Diagnosis was based on clinical elements and CT scan was used to measure pathology and program surgery. Treatment was modified radical mastoidectomy associated with meatoplasty. Due to the insidious character of CEAC and the proximity with important structures of the external auditory canal, it must be always considered in differential diagnosis for lesions of external auditory canal. This case report intended to review clinical and surgical aspects of treatment of CEAC and present our approach in a case with severe lesions.