Mohs Micrographic Surgery

The majority of skin cancers are relatively easy to remove completely by excision or curettage, but where maximum conservation of tissue is required, and with difficult tumours Mohs’ surgery is very valuable and results in the highest cure rates.

The bulk of the tumour is removed by curette or knife and then a saucer shape piece of skin all around Is taken. This is marked with dyes corresponding to nicks made in the patient’s skin. The specimen is then flattened, frozen and then cut in horizontal layers from the underside upwards In a cryotome. The result is a series of slides that can be read like a map, enabling the operator to go back precisely to the place where tumour remains, and repeat the process until complete clearance (ie slides negative for tumour) is obtained. The resulting defect can then be repaired using conventional techniques. Even with problem and recurrent tumours cure rates of weIl over 95% can be obtained.

Indications for Mohs

• Morphoeic tumours
• Recurrent tumours
• Tumours in ‘Emryonic folds’
• Maximum conservation of tissue
• Medico-legal?