Clinical Characteristics of Non-Melanoma Skin Cancers Recurring within 5 years after Mohs Micrographic Surgery: Single Institution Retrospective Chart Review

Background: Mohs micrographic surgery (MMS) is used to treatcertain high-risk non-melanoma skin cancers (NMSC) due to its highcure rate. However, clinical recurrences do occur in a small numberof cases. Objective: We examined specific clinical characteristicsassociated with NMSC recurrences following MMS. Methods: We employed a retrospective chart review of the 1467cases of NMSC that underwent MMS at UC San Diego from January 1,2008 through December 31, 2009. A total of 356 cases were excludeddue to lack of follow-up. Results: Five (0.45%) of 1111 cases developed recurrencesof NMSC at the site of MMS. There were 741 cases of basal cellcarcinomas (BCC); 3 were recurrences (0.40%). There were 366 casesof squamous cell carcinomas (SCC); 2 were recurrences (0.55%).Review of MMS histopathology of these recurrent tumors showed thatthere were no errors or difficulty with the processing or interpretationof the slides. Conclusion: Five-year recurrence rate of NMSC following MMSat our institution is below the reported average. Our retrospectivechart review identified specific clinical characteristics associated withNMSC recurrence including a history of smoking, anatomical locationon the cheeks, ears or nose, and a history of immunosuppression forSCCs.