Quantification of the surgical margin shrinkage in lip cancer: determining the relation between the surgical and histopathologic margins.

Lip carcinoma is one of the most common cancers of the head and neck region. Lower lips are more frequently affected. Squamous cell carcinoma accounts for more than 95% of the cases. The aim of treatment is to achieve the highest cure rates with adequate excision with clear surgical margins while leaving the smallest defect sizes behind for reconstruction. Excised tissue is known to shrink when removed, in relation with its retractile properties. In this study, the evaluation of the amount of shrinkage in excised lip cancer specimens and determination of the relation between surgical and histopathologic margins were aimed. The study included 21 consecutive excised lip specimens for the treatment of squamous cell carcinoma of the lip. The volume of the specimen, tumor length, and margin distance measurements were measured and recorded step by step from before surgical excision to histopathologic evaluation. Specimens were evaluated in a standardized fashion by the same pathologist after 48 hours of fixation. For data analysis, Number Cruncher Statistical System 2007 and Power Analysis and Sample Size 2008 Statistical Software (Kaysville, UT) were used. The surgical margins of the excised lip specimen shrink up to 41% to 47.5% from before excision to histopathologic evaluation. The most significant step was the excision step, followed by the formalin fixation step. The histopathologic process itself and the duration of formalin fixation did not result a significant change in surgical margins. The tumor tissue itself did not show a significant shrinkage.