Immunohistochemical analysis of the ras oncogene protein product in human thyroid neoplasms.

: The monoclonal antibody Y13 259 to the ras oncogene p21 product was used in an immunohistochemical study of ras expression in human thyroid neoplasms. Both papillary and follicular carcinomas showed consistently higher staining intensity than normal tissue adjacent to carcinomas. Some follicular, foetal, embryonal and oxyphil adenomas exhibited higher staining intensity than normal tissue. Our results suggest that elevated ras expression may be important in the development of some adenomas and in their conversion to carcinomas.