Lymphocytes in the epithelial layers of decidua and normal or abnormal endometrium.

Lymphocytes in the endometrium were counted during infancy, the reproductive age including pregnancy and the postmenopausal era and in various pathological states (cystic-glandular hyperplasia, adenomatous hyperplasia, endometrial polyposis, endometrium after long-standing ingestion of oral contraceptives, endometrial carcinoma). Compared with the child-bearing era, the lymphocyte concentrations in endometrium were markedly lower during infancy and after the menopause. Lymphocyte concentrations were high in cystic-glandular hyperplasia, endometrial carcinoma and pregnancy, and low in focal adenomatous hyperplasia and endometrial polyposis. Although histological examination of the endometrium after long-standing ingestion of oral contraceptives showed atrophy, the lymphocyte count was high.