Characteristics of squamous cell carcinoma in situ of the ear treated using Mohs micrographic surgery

Mohs micrographic surgery (MMS) is used to treat squamous cell carcinoma in situ (SCCIS) for tissue conservation.

To examine characteristics of patients with SCCIS of the external ear treated using MMS.

A retrospective review from 2005 to 2011.

We identified 173 cases of SCCIS of the ear. The population was 94% male (p < .01), with a mean age of 71. Eight percent (n = 13) of tumors were recurrent after prior treatment. Recurrent tumors occurred exclusively in men and were associated with larger initial size (p = .05), more layers for clearance p = .059), and larger final defect size (p = .01). Tumors with larger initial area were independently associated with older age (p < .01). Complexity of repair was independently associated with more layers (p < .01), larger initial area (p = .01), and larger final area (p = .02). Sex did not affect repair type.

SCCIS of the ear predominantly affects men in our referral base of 85% to 90% private patients and 10% to 15% veterans. Recurrent tumors were associated with larger initial size and subclinical spread of tumor. Primary tumors on average required 1.6 layers, validating the utility of MMS in this population in delineating the subclinical spread of SCCIS of the ear.