IMPROVEMENT OF DIAGNOSTIC-ACCURACY OF TRANSVAGINAL ULTRASOUND FOR IDENTIFICATION OF ENDOMETRIAL MALIGNANCIES BY USING CUTOFF LEVEL OF ENDOMETRIAL THICKNESS BASED ON LENGTH OF TIME SINCE MENOPAUSE

Transvaginal ultrasonography (TVS) is considered useful for identifyin g endometrial malignancies, but it has a low specificity and a high fa lse-positive rate. The purpose of this study was to improve the specif icity of this technique. A total of 300 postmenopausal women were stud ied. They were clinically evaluated by TVS and endometrial histology. Twenty women yielded pathologic findings on endometrial examination. T he mean endometrial thickness was related to the length of time since menopause. For endometria with pathological findings, sonographic meas urements of endometria with a thickness of greater than 3 mm exhibited 95.0% sensitivity, 68.5% specificity, 19.4% positive predictive value , and 99.4% negative predictive value. If a 4-mm cutoff limit was used for <5 years since menopause and a 3-mm cutoff limit was used for gre ater than or equal to 5 years since menopause, 95.0% sensitivity, 78.1 % specificity, 25.7% positive predictive value, and 99.5% negative pre dictive value were obtained. The specificity and false-positive rate w ere improved when the cutoff limit was decided based on the length of time since menopause. The cutoff level of the endometrial thickness fo r detection of endometrial malignancies should be decided based on the length of time since menopause. (C) 1997 Academic Press