IMMUNOHISTOCHEMICAL DETECTION OF THE C-MYC ONCOGENE PRODUCT IN NORMAL, HYPERPLASTIC AND CARCINOMATOUS ENDOMETRIUM

The expression and the distribution of the c-myc oncogene product (p62 ) was studied by a 3-step immunoperoxidase technique using the monoclo nal antibody myc 1-6 E10 in 22 cases of normal endometrium (11 prolife rative and 11 secretory phase), 43 endometrial hyperplasias (24 adenom atous and 19 adenocystic) and 26 endometrial carcinomas. Increased exp ression of c-myc product appeared in endometrial carcinomas compared w ith respective non-neoplastic tissue (p < 0.001). The immunolocalizati on of the c-myc protein shows a consistent difference between the vari ous histologic patterns of nonneoplastic and neoplastic endometrium. N uclear staining of the c-myc product was demonstrated in epithelial ce lls of the proliferative phase and predominantly in poorly differentia ted forms of endometrial carcinomas. On the other hand cytoplasmic sta ining was found predominantly in the secretory phase and in well diffe rentiated carcinomatous endometrium. In hyperplastic endometrium an in termediate immunohistochemical pattern was observed. The results of th e present study emphasize that c-myc product overexpression and locali zation plays an important role in initiation, differentiation and prog ression of endometrial carcinomas.