Carbohydrate Antigens as Oncofetal Antigens in Papillary Carcinoma of the Thyroid Gland.

The expression of simple mucin-type antigens, Lewis type-1 antigens, and Lewis type-2-related antigens was evaluated by immunohistochemistry in a series of nine fetal thyroid glands. The aim of the study was to establish whether the previously reported expression of carbohydrate antigens in thyroid carcinomas represents a "de novo" expression or a form of the so-called oncofetal expression. We have detected simple mucin-type antigens and Lewis type-2-related antigens in fetal thyroid tissue. Lewis type-I antigens were not found. Taking the results of this study together with those previously reported, we conclude that the presence of Lewis type I antigens in thyroid carcinomas appears to be a "de novo" expression, whereas the constant and strong expression of simple mucin-type antigens and Lewis type-2-related antigens represents a re-expression (oncofetal expression) of antigens already present during fetal life.