Iatrogenic endometrial patterns
The histological patterns exhibited in the endometrium due to the newer progestational agents cannot be correlated with the patient's menstrual cycle or the physiological endometrium which follows ovulation. The oral progestational agents which have been produced during the past few years have had wide clinical application. Although the 19-nor-steroids and the derivatives of 17 αhydroxyprogesterone differ in chemical structure, they produce similar histological appearances in the endometrium. Prolonged use of these compounds produces atrophy of the endometrial glands and a cellular stroma which might be mistaken for endometrial sarcoma. In view of the fact that such compounds are widely used in clinical practice and as contraceptive agents, it is essential that the pathologist should be aware of the bizarre endometrial patterns which they may produce; the more important of these changes are illustrated and discussed.