[Detection of a cross-reacting antigen common to multilaminar epithelia and group A streptococcus in cells of human epidermal tumors].

The tissue-specific antigen of basal cells of human squamous epithelium which cross-reacts with streptococcal group A antigen has been detected in the cytoplasm of cells of human basal cell and squamous cells carcinomas histogenetically related to the skin epithelium. The antigen has not been detected in cells of tumors of endodermal origin (gastric and intestinal adenocarcinomas). These findings together with previous reports on the existence of cross-reactivity in case of animal tumors of ectodermal genesis may form the basis for an additional method of differential diagnosis of human tumors arising from the ectoderm-derived epithelium.