[Mohs micrographic surgery]

Mohs micrographic surgery is a surgical technique allowing for nearly 100% histological analysis of the margins of a removed skin tumor, unlike conventional surgery which only analyzes a small portion (around 5-6%). The most common method ("frozen section") involves excising the tumor with minimal margins, spatially orienting the specimen using dyes, then freezing it for sectioning and immediate microscopic analysis by the surgeon themselves. If tumor cells remain at the edges, the surgeon re-operates only the affected area on the same day until clear margins are achieved before reconstruction. A variation, "slow Mohs", uses analysis on paraffin-fixed tissue with a delay. Mohs surgery significantly reduces recurrence rates for carcinomas (basal cell and squamous cell) compared to standard surgery and better preserves healthy tissue. It is recommended by European and American authorities for high-risk skin cancers and is considered mandatory for dermatofibrosarcoma protuberans.