Sonographic depiction of normal and abnormal endometrium with histopathologic correlation.

The sonographic appearance of the endometrium was correlated to histopathologic findings in 38 patients who underwent hysterectomy. The thickness was accurately assessed by sonography (within +/- 1 mm) in 33 of 38 patients. The hypoechoic halo which surrounds the endometrium was found to represent the inner third of the myometrium which is relatively vascular and compact. In postmenopausal patients who are not receiving hormonal replacement, an endometrium of greater than 5 mm should be considered abnormal. Several causes of abnormally thick endometrium were encountered in this study, including endometrial carcinoma, hyperplasia, adenomyosis, hematometria, mucometria, and pyometria. Sonography was found to be accurate in determining the depth of myometrial invasion in adenocarcinoma.