False-negative rate of intraoperative frozen section margin analysis for complex head and neck nonmelanoma skin cancer excisions.

Introduction: Intraoperative frozen section analysis (IFSA) is traditionally performed for complex and high-risk non-melanoma skin cancer (NMSC) resections, particularly when surgery under a general anaesthetic and a complex reconstruction is required, and where Mohs micrographic surgery (MMS) is not available.
Methods: A retrospective audit of 253 cases between 1999 and 2009 was undertaken, investigating the accuracy and efficacy of IFSA for the treatment of NMSC in our tertiary skin tumour unit based in a university hospital setting.
Results: The combined incomplete and very narrow (<1 mm) excision margin rates were 28.7% and 27.5% for basal cell and squamous cell carcinoma, respectively. Unrepresentative sampling of the excision margins intraoperatively was the overwhelming cause of error (94%).
Conclusion: After a thorough audit of our data, IFSA has been abandoned for the treatment of NMSC in our unit. MMS is practised intraoperatively, even in advanced cases. We believe that IFSA no longer has any role in our complex, multidisciplinary skin cancer practice.
(© 2015 British Association of Dermatologists.)