Non-Melanoma Skin Cancer Tumor’s Characteristics and Histologic Subtype as a Predictor for Subclinical Spread and Number of Mohs Stages required to Achieve Tumor-Free Margins

Abstract

Objective: To describe the behavior of non-melanoma skin cancer (NMSC) based on tumor’s characteristics. Methods: A total of 219 of NMSC were analyzed via a retrospective medical chart review. The data obtained from each record included but was not limited to: number of Mohs micrographic surgery (MMS) stages required for tumor clearance, defect size, repair type and size according to the neoplasm’s histopathologic subtype. Results: The mean number of stages required to clear morpheaphorm/infiltrative and micronodular basal cell carcinomas (BCCs) (n= 34) was 2.03, while the nodular and superficial BCCs (n= 125) needed a mean of 1.56 stages (p value= .034). Of the tumors located on a high-risk zone, 59.6% required two or more stages to be cleared while 67.7% of the lesions on a non-high risk zone were cleared with one stage (p value = 0.001). Recurrent tumors required a mean 2.22 MMS stages to be cleared, whereas primary tumors required a mean 1.61 stages (p value= .006). Conclusion: Subclinical spread was seen in morpheaform/infiltrative and micronodular BCC histologic subtypes, recurrent tumors, and tumors in high-risk locations. These could help predict aggressive tumor behavior and optimize surgical planning.