Intra-epithelial carcinoma concomitant with esophageal squamous cell carcinoma

A review of 222 cases of squamous cell carcinoma of the esophagus revealed 67 (30.2%) with intra-epithelial carcinoma, contiguous with the main lesion. The incidences of such lesions were 10.9% and 68.0% in those given and not given preoperative irradiation, respectively. The 222 tumors were grouped into five categories, according to depth of invasion of the main lesion, those restricted to the mucosa, submucosa, proper muscular layer, and those invading the adventitia and neighboring structures. The rates of occurrence of intra-epithelial carcinoma were 87.5, 65.0, 26.9, 18.8, and 17.7%, respectively. Of the 67 with intra-epithelial carcinoma, the incidences of both proximal and distal location of such lesions were 85.7% in mucosal carcinoma, 84.6% in submucosal carcinoma, 71.4% in cancer restricted to the proper muscular layer, 50.0% in cancer invading the adventitia, and 9.1% in cancer invading the neighboring structures. Intra-epithelial carcinoma may thus originate from field carcinomatous transformation rather than from an intra-epithelial spread of the main lesions. These observations also support the concept of the field origin of carcinogenesis in the esophagus.