Background: An evaluation of the safe resection margin in esophagectomy or esophageal endoscopic mucosal resection for carcinoma, based on serial histologic investigations by measuring the length of subepithelial extension of the lesion beneath the noncancerous epithelium, has not been reported.
Methods: Forty-eight patients with esophageal carcinoma restricted to within the esophageal wall including 67 lesions (27 mucosal, 27 submucosal cancer, and 13 lesions of cancer invading to proper muscular layer) were histopathologically examined. The length of subepithelial extension (SEE) beneath the noncancerous epithelium of each lesion was measured and the clinicopathologic significance of SEE was discussed.
Results: Among these 67 lesions in 48 cases, there were 17 (25.4%) lesions with SEE. The rates of coexistence of SEE were 3.7, 37.0, and 46.2% in mucosal and submucosal cancer, and cancer invading the proper muscular layer, respectively. When the positive rate was more than 50% for the factors of SEE--lymphatic permeation, blood vessel permeation, and intramural metastasis--the prognosis was significantly poorer in the patients with esophageal cancer.
Conclusions: When the lesion was restricted to within the mucosal layer, SEE was almost negligible at resection. The coexistence of SEE was thus found to be one of the prognostic factors predicting a poor prognosis.