[Role of intraepithelial lymphocytes in the development of bladder tumors]

Morphometry of lymphocytic infiltration of bladder tumour parenchyma was performed. In human bladder tumours, the positive correlation between the number of intraepithelial lymphocytes and stages of tumour progression was found. The same correlation between the degree of lymphocytic infiltration of tumour parenchyma and the rate of tumour cell proliferation was observed when historadioautographs of experimental rat bladder neoplasms were analysed. The lack of tumour cell degeneration and necrosis in the areas of intraepithelial lymphocyte accumulation and the presence of these processes in lymphocytes were noted. The data obtained give a new insight into the role of lymphocytes in tumours and confirm, although indirectly, the ability of lymphocytes to maintain or stimulate tumour growth.