Comparison of estrogen-induced hyperplasia to endometrial carcinoma

Use of exogenous estrogens has been associated with endometrial cancer in a number of case-control studies. This observed association could be biased as a result of frequent misclassification of estrogen-induced hyperplasia as endometrial cancer. To evaluate this possibility, pathology slides from 233 patients with a hospital diagnosis of endometrial cancer were reviewed independently by two pathologists. The hospital diagnosis was confirmed by both pathologists in 86% of the cases, indicating that the misclassification of hyperplasia as carcinoma is uncommon.