Objective: The safe resection margin in esophagectomy for esophageal squamous cell carcinoma (SCC) was determined based on the extent of epithelial and subepithelial accessory lesions from the main lesions of esophageal SCC.
Background: There have been many reports on the high incidence of a positive resection margin for esophageal cancer. Although there were some studies on the relationships of the proximal clearance to postoperative local recurrence, no pathologic study on the resection margin has been reported.
Methods: Four hundred twenty specimens of a whole resected esophagus were examined histopathologically and the longitudinal length from the main lesion to the five types of accessory lesions was measured on microscopic slides.
Results: Contiguous intraepithelial carcinoma existed in 69 (46%) of 150 sites of main lesions restricted to the mucosa or submucosa and subepithelial lesions existed in 131 (54%) of 245 sites and 82 (55%) of 150 sites of main lesions invading an adventitia and into neighboring structures, respectively. The risk of a positive resection margin due to subepithelial lesions was below 5% at 10 mm in the main lesion, restricted to the submucosa or the muscularis propria, and at 30 mm in the main lesion, invading the adventitia in the potentially curative operation cases.
Conclusion: These clearances of the resection margin, in which the risk of a positive resection margin is below 5%, are acceptable, although these clearances should only be accepted after the extent of epithelial accessory lesions is accurately determined by the Lugol's stain method.