[Degree of lymphocytic infiltration of the epithelium in bladder tumors]

Lymphocytic infiltration of parenchyma and stroma of transitional cell tumors of human urinary bladder was assessed separately by quantitative morphometric procedures. The study established an increased level of lymphocytic infiltration of urothelium in areas adjacent to tumor matched by a relevant decrease in simple papillomas. Infiltration level remained unchanged in proliferating papillomas and papillomas with multiple carcinomas in situ. This parameter was raised in papillomas with local cell atypia, local invasion and single carcinomas in situ as well as in transitional cell cancers. These data are in collision with the hypothesis of progressive failure of cell-mediated immunity in tumorigenesis. The results suggest tumor growth stimulation by lymphocytes.