Background: Patients with basal cell carcinoma and cutaneous squamous cell carcinoma are at substantial risk for the onset of a second nonmelanoma skin cancer (NMSC).
Objective: Our purpose was to determine the incidence of multiple (synchronous) NMSC at presentation to an academic Mohs micrographic surgery referral center and to note the incidence of second lesions occurring in a metachronous fashion.
Methods: A retrospective study was conducted of 456 consecutive patients who presented for Mohs surgery over a 2-year period. Patients were assessed at initial visits for the presence of multiple NMSCs and were subsequently examined over 2 years for the onset of new NMSCs.
Results: More than 39% of patients initially referred for Mohs surgery with a basal cell or squamous cell carcinoma either presented with multiple primary lesions or experienced a subsequent NMSC within 2 years. These tumors were divided almost equally between multiple primary NMSC at presentation and subsequent (metachronous) tumors.
Conclusion: Patients referred for Mohs surgery in an academic setting are a select group at extremely high risk of additional NMSCs at or shortly after presentation for the index lesion.