Transvaginal ultrasonography and endometrial histology in peri- and postmenopausal women on hormone replacement therapy

Objective To determine the association between endometrial thickness and endometrial histology in a large sample of women using HRT. Design Results from three multi-centre studies were combined. Participants Five hundred and sixty-four climacteric women were treated with either sequential, continuous combined or long-cycle therapy. Main outcome measures The women underwent 717 examinations with both transvaginal ultrasonography and histological examination of the endometrium. Endometrial thickness was measured and associated with the histological findings. Results Eight cases of endometrial hyperplasia were diagnosed. All the hyperplasias were simple without atypia. Two cases had an endometrial thickness < 4 mm and two a thickness > 8 mm. The > 4 mm threshold for abnormal endometrium had a sensitivity of 75%, a specificity of 47%, a positive predictive value of 2% and a negative predictive value of 99%. Conclusion No association could be found between the endometrial thickness measured by transvaginal ultrasonography and endometrial pathology. In six out of eight women with simple hyperplasia the endometrium measured > 4 mm.