Purpose: Mohs micrographic surgery has been advocated as the optimal management of nonmelanoma skin cancer in the periocular region. It is a technique that is ideally suited to the removal of skin tumours with a contiguous growth pattern such as basal cell carcinoma and squamous cell carcinoma, allowing examination of 100% of the surgical margin. As a result of this total margin control, the technique offers an unsurpassed curve rate combined with maximal preservation of normal tissue. Following excision of a periocular tumour by a Mohs surgeon, the resulting defect usually requires reconstruction. Our objective was to determine whether the size of defect produced by Mohs surgery and the type of reconstruction required differed from the results we would have expected from standard surgery with a 3 mm excision margin.
Methods: A Mohs surgery service with a combined dermatological and oculoplastic approach was set up in Manchester in 1994. We reviewed 60 of our patients who underwent Mohs surgery and compared the size of defect produced as well as the type of reconstruction required with the results we would have predicted for standard excisional surgery with a 3 mm margin.
Results: Although a minority of patients required larger reconstructions than would have been anticipated (20%), many had smaller reconstructions than we had predicted (37%). This latter group often had important structures preserved, and therefore had the benefit of less extensive reconstructive surgery.
Conclusions: Excision of a periocular tumour by Mohs surgery may occasionally identify extensive subclinical tumour extension and so produce an unexpectedly large defect for reconstruction. Many patients, however, require less extensive reconstructive surgery than would have been predicted. This produces benefits in terms not only of improved cosmesis and eyelid function, but also reduced operating theatre costs.