A retrospective study of outcome of Mohs' micrographic surgery for cutaneous squamous cell carcinoma using formalin fixed sections.

The surgical management of recurrent or large squamous cell carcinoma (SCC) can be challenging as tumours often extend beyond visible margins. Micrographic surgery is a potentially effective method of ensuring complete clearance of tumour. A retrospective study of all cases of SCC treated by micrographic surgery in this department between 1986 and 1996 has been done. Sixty-one patients were treated using a formalin-fixed paraffin-embedded tissue technique with a median follow-up of 4 years. In two cases there was local recurrence and in three others metastasis to local lymph nodes. The overall cure rate was 92% (56 of 61), which compares favourably with published series using chemosurgery and frozen tissue techniques. The results show that this technique of micrographic surgery is a satisfactory and cost-effective alternative to conventional frozen section techniques in the treatment of SCC. The formalin-fixed tissue method has the advantage of providing high-quality permanent histological sections using existing conventional pathology services.