Origin and spread of intra-epithelial carcinoma of the esophagus. Histopathologic investigation of the junctions between intraepithelial carcinoma and non-cancerous epithelium.

Scrutinization of data on 56 patients of primary esophageal squamous cell carcinoma and not given preoperative irradiation therapy disclosed 36 areas (64.1%) of intra-epithelial carcinoma contiguous to the main lesion, and in 16 (28.7%) there was a multiple occurrence of squamous cell carcinoma, in which 13 were double and 3 were triple carcinomas. A total of 96 junctions between intra-epithelial carcinoma and non-cancerous epithelium were histologically investigated. These junctions could be grouped into two types: well-demarcated (29 areas, 30.2%) and ill-demarcated (67 areas, 69.8%) types. The latter was separable into 12 (12.5%) of whole layer, 33 (34.4%) of basal layer and 22 (22.9%) of irregular patterns. Epithelial dysplasia occurred in one (3.4%) of well-demarcated and ten (14.9%) of ill-demarcated junctions, and almost all lesions of dysplasia were moderate or severe. Thus, most carcinomatous transformation had occurred at the site of junction (in-situ carcinogenesis) and epithelial dysplasia may be a carcinoma rather than pre-cancerous lesion, per se.