Immunohistochemical study of estrogen and progesterone receptors in normal, hyperplastic and malignant endometrium

ABSTRACT

A series of 44 cases of various human endometrial tissues were immunohistochemically stained for estrogen receptor [ER] and progesterone receptor [PR] using formalin -fixed, paraffin - embedded sections. ER/PR content was evaluated in the epithelium, stroma and myometrium according to the percentage of positive cells and the intensity of nuclear stain. The receptor content was highest in the proliferative epithelium and decreased gradually throughout the postovulatory phase of the menstrual cycle in both the epithelium and the stroma. ER / PR content was high both in the epithelium and stroma of hyperplasia without atypia and was thus similar to that of the proliferative endometrium. The receptor content was very low in the epithelium and stroma of hyperplasia with cytologic atypia. In carcinomas, there was a heterogeneous distribution of ER and PR both in the epithelium and stroma, but in general, the receptor content was low as compared with normal proliferative or hyperplastic endometrium without atypia. Endometrioidtype adenocarcinomas including those with squamous differentiation had the highest degree of positivity for both receptors. Tumors with architectural grade 3 were significantly immunostained less than those with 2 or 1 grades. Carcinomas with nuclear grade 3 were unstaind. The low grade endometrial stromal sarcoma was positive for both receptors, while the high - grade one was negative. The degrees of ER and PR positivity correlated with each other. There was no correlation between the patient's age and ER / PR categories. The results of this study indicate that immunohistochemical analysis of sex steroid receptor status on formalin -fixed, paraffin - embedded tissues offers good alternative to the standard biochemical procedure