Surgery for the Primary Lesion

In a review of 18 case series, 279 of 926 patients (30.1%) developed local recurrence during follow-up, excluding those presenting with distant metastatic disease at presentation. These recurrences have been typically attributed to inadequate surgical margins or possibly a lack of adjuvant radiation therapy.[2,3]

Given the propensity of MCC to recur locally (sometimes with satellite lesions and/or in-transit metastases), wide local excision to reduce the risk of local recurrence has been recommended for patients with clinical stage I or stage II disease.

Recommendations about the optimal minimum width and depth of normal tissue margin to be excised around the primary tumor differ among the various retrospective case series, but this question has not been studied systematically.[3-7][Level of evidence C2] No definitive data suggest that extremely wide margins improve overall survival (OS), although some reports suggest that wider margins appear to improve local control.[3][Level of evidence C2] Frozen-section evaluation of margins may be useful, especially when the tumor is in an anatomical site that is not amenable to wide margins.

Some authors have advocated the use of Mohs micrographic surgery as a tissue-sparing technique. The relapse rate has been reported to be similar to or better than that of wide excision, but comparatively few cases have been treated in this manner and none in randomized controlled trials.[7-10][Level of evidence C2]