Microscopically oriented histologic surgery for head and neck mucosal cancer

Frozen section directed surgery, called MOHS, has been successfully utilized in the resection of primary epidermoid tumors of the head and neck. For the 93 cases reviewed in this study, 70% had microscopically identified tumor 1 cm away from clinically evident disease. Tumor spread was along planes of least resistance, most commonly in the submucosa. Microscopically directed excisions were able to trace and remove these tumor extensions. Local control in 93 patients with 2-year follow-up was 91% and, with salvage of recurrences, was 95%. The authors' observations suggest three important concepts. First, epidermoid cancer of the head and neck grows as a continuous neoplasm. Second, this work casts serious doubt on the concept of "field cancerization" or multiple primaries as a cause of local recurrence. Third, conventional frozen section analysis of surgical margins is highly unlikely to discover microscopic extensions because many tumor extensions are thin, finger-like projections which require examination of the entire surgical margin to detect.