Carcinomatous invasion and lymphocyte infiltration in early esophageal carcinoma with special regard to the basement membrane. An immunohistochemical study.

We examined 24 cases of superficial esophageal carcinoma and evaluated 94 areas, including 43 intra-epithelial (ep), 36 mucosal (m) and 15 submucosal (sm) areas, using the immunohistochemical staining of laminin to detect the basement membrane. The staining pattern was divisible into three patterns, i.e., continuous, fragmentary and defective. Defective patterns were observed in 14%, 53%, and 73% of the ep, m, and sm lesions, respectively (p < 0.01). With regard to the degree of lymphocyte infiltration, 77% of the continuous areas were accompanied by a low lymphocyte infiltration, while 56% of the defective areas were accompanied by dense infiltrations with follicle formation. Lymphocyte infiltration was thus statistically significantly (p < 0.01) more closely associated with the defective areas than with the continuous areas. Furthermore, urokinase-type plasminogen activator was detected immunohistochemically in 11.1% of the defective areas, and in none of the continuous areas. These findings suggested 1) that superficial esophageal carcinoma might progress while destroying the basement membrane, and 2) that as host immune reactions lymphocytes might infiltrate the lesions where the basement membranes were destroyed and cancer cells exposed to the underlying layer. The findings also suggested the possibility that the degradation of the basement membrane might be caused by proteolytic enzymes produced by cancer cells.