Modified keystone flap for extremity defects after Mohs surgery.

Background: When possible, surgery is the treatment of choice for cutaneous carcinomas, as it allows to us perform the anatomopathological study and control the surgical margins. Mohs micrographic surgery (MMS) controls 100% of the margins, maintains a larger amount of healthy tissue, and a fewer number of recurrences are seen. Large limb surgical defects after MMS are a challenge.