Objective: To determine the diagnostic accuracy of transvaginal ultrasonography (TVS) and hysteroscopy for the diagnosis of endometrial pathology in postmenopausal women with abnormal uterine bleeding (AUB).
Design: This prospective nonrandomized study was conducted on 752 postmenopausal women with AUB who underwent TVS and outpatient hysteroscopy with eye-directed biopsy. Histologic diagnoses were compared with the ultrasonographic and hysteroscopic findings, and the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were determined.
Results: In three cases of atrophic endometrium on hysteroscopy, histologic examination revealed endometrial carcinoma. TVS using an endometrial thickness of less than 4 mm as the cutoff showed sensitivity of 89%, specificity of 86%, a positive predictive value of 82%, a negative predictive value of 92%, and diagnostic accuracy of 87%. Hysteroscopy was technically successful in all women and revealed sensitivity of 98%, specificity of 91%, a positive predictive value of 88%, a negative predictive value of 98%, and diagnostic accuracy of 94%.
Conclusions: Hysteroscopy is a significantly more accurate diagnostic method for the detection of endometrial pathology than TVS, has better specificity, and should be considered for all patients with AUB with an endometrial thickness of more than 4 mm. Hysteroscopy shows great efficiency in the diagnosis of focal abnormalities of the endometrium, which are unlikely recognized by ultrasonography and should be indicated in cases of AUB with an endometrial thickness less than 4 mm on ultrasonography because of the possibility of missing infrequent (0.8%) but relevant endometrial pathologies. Among such women showing abnormal or suspicious lesions, it is necessary to perform hysteroscopy with eye-directed biopsy because some cases of endometrial carcinoma could be missed.