DS28 Mohs micrographic surgery for non-basal cell carcinomas: a national survey on current practice in the UK

Abstract

Mohs micrographic surgery (MMS) is established for treating basal cell carcinomas (BCCs). However, UK provision for non-BCC tumours remains variable. We aimed to assess UK non-BCC Mohs practice, including workforce capacity, pathology support, barriers to delivery, attitudes towards non-BCC service expansion, and engagement with the British Society for Dermatological Surgery (BSDS) national MMS logbook. A survey of UK dermatology Mohs surgeons was performed. Quantitative and qualitative data were collected on departmental staffing, annual Mohs caseload, the proportion and spectrum of non-BCC tumours treated, pathology arrangements, willingness to ring-fence non-BCC specific Mohs slots, and utilization of the BSDS national Mohs logbook. In total, 37 responses were received, with broad regional representation. Most departments reported two to three substantive Mohs surgeons, typically supported by one to two technicians per list. Overall, 41% of respondents worked in units undertaking > 500 Mohs cases annually. Non-BCC cases represented on average 5–10% of the workload; 25% of respondents reported < 5%. Non-BCC tumours treated with MMS included squamous cell carcinoma (SCC), lentigo maligna (LM) and dermatofibrosarcoma protuberans (DFSP). Overall, 82% of departments used paraffin-­embedded horizontal sections for DFSP and LM. Pathology turnaround varied from days to weeks. While some centres undertook multiple cases of SCC Mohs per week, barriers emerged for others. These were predominantly structural, including pathology capacity, nonstreamlined pathways, cancer waiting times and impact on BCC throughput. In total, 84% of respondents supported, in principle, allocating two to four SCC slots per month. Engagement with the BSDS Mohs logbook was variable; 42% reported regular use, and one-third never engaged. Time was the most commonly cited barrier. There is an appetite among UK Mohs surgeons to expand non-BCC MMS provision. However, system-level constraints and treatment ‘targets’ remain significant obstacles. Sharing of service models, development of streamlined multidisciplinary pathways, and improved engagement with the BSDS logbook may support benchmarking and inform consensus on appropriate non-BCC Mohs case volumes, facilitating more equitable national service provision.