Cancer recurrence following Mohs micrographic surgery: a mechanism of tumor persistence.

Abstract

Recurrence of basal cell carcinomas after Mohs micrographic surgery is rare but known to occur. This report describes the recurrence of a basal cell carcinoma of the forehead after Mohs surgery in order to illustrate a previously undescribed mechanism of tumor persistence and recurrence despite thorough microscopic evaluation of all surgical margins. The value of the surgeon's reviewing all prior histologic sections before performing micrographic surgery, the importance of resecting all scar tissue from a previous surgical site prior to determination of tumor-free margins, and the potential usefulness of a three-tiered closure after excision of a cutaneous malignancy that involves the muscular layer are discussed.