Post–Mohs Micrographic Surgical Margin Tissue Evaluation with Permanent Histopathologic Sections

Abstract

Background Incomplete resection of nonmelanoma skin cancer is associated with a relatively high rate of recurrent tumors. Mohs micrographic surgery provides microscopic evaluation of tumor margins to ensure complete excision of nonmelanoma skin cancers at high risk of recurrence. Objective This purpose of this study is to confirm the histologic accuracy of Mohs excision of facial skin cancers by evaluating an additional layer of tissue with permanent histopathologic sections after Mohs excision. Methods Two hundred ninety-six Mohs cases were identified, which, after excision, were sent to a single plastic surgeon for reconstruction. This plastic surgeon routinely takes an additional layer and sends for permanent histopathologic evaluation at the time of reconstruction. A review of the pathology reports and tissue specimens on these patients provides valuable data on tumor margins and the effectiveness of the Mohs technique for tumor excision. Results Two excisions of nodular basal cell cancer were determined by the pathologist to have positive tumor involvement on post-Mohs permanent tissue. On additional review, one specimen was interpreted to be more consistent with follicular epithelium, and the second was verified as a focus of nodular basal cell cancer. Conclusion These data support the high reliability of Mohs surgery for margin control.