Primary cholesteatoma of the external auditory canal: is the epithelial migration defective?

Primary cholesteatoma of the external auditory canal (EACC) is a rare disease, characterized by osteonecrosis with formation of sequesters and ingrowth of keratinizing squamous epithelium in the bony EAC. The aetiology and pathogenesis are unknown, but an earlier study has demonstrated abnormal epithelial migration in such ears. The present study explored whether this interesting result can be reproduced.

The epithelial migration in 10 ears with EACC was studied using the ink-dot method. Two ears with minor lesions were studied before treatment, and 8 ears were studied after operation or conservative treatment. The results were compared with the migration in 15 normal ears examined in a previous study using the same method.

Tertiary referral center.

1) Presence or absence of epithelial migration; 2) change of the normal centrifugal pattern; and 3) estimated migration speed compared with normal ears.

A qualitatively normal centrifugal migration was present on intact (unaffected or healed) skin in all 10 ears with EACC and was only missing directly on crust-covered lesions. The estimated migration speed was similar to the speed in normal ears, that is, approximately 150 mum/d.

Ears with EACC seem to have qualitatively and quantitatively normal epithelial migration except directly on crust-covered lesions. It is unlikely that an abnormal epithelial migration is involved in the pathogenesis of this disease. These observations have implications for EAC disorders with similar clinical features that involve bony invasion, including osteoradionecrosis.