Adenomyosis: three-dimensional sonographic findings of the junctional zone and correlation with histology

OBJECTIVE: To correlate with histopathological features the adenomyosis-induced morphological alterations of the outer myometrium and the inner myometrium ('junctional zone', JZ) detectable on two- (2D) and three-dimensional (3D) transvaginal ultrasound imaging (TVS), and to evaluate their diagnostic accuracy for adenomyosis. METHODS: Premenopausal patients scheduled for hysterectomy for benign pathology were enrolled in this prospective study. Before hysterectomy all patients underwent detailed 2D-TVS and 3D volume acquisition of the entire uterus. The major sonographic signs of adenomyosis were noted. On the multiplanar coronal and longitudinal views obtained by 3D-TVS we measured the maximum and minimum JZ thickness from the basal endometrium to the internal layer of the outer myometrium (JZmax, JZmin), the difference between them (JZdif = JZmax - JZmin) and the ratio JZmax/total maximum myometrial thickness. Results of these examinations were correlated blindly to the presence of adenomyosis on histological specimens. RESULTS: A total of 72 premenopausal patients underwent 2D- and 3D-TVS before hysterectomy. The histological prevalence of adenomyosis was 44.4% (32/72 patients). In diagnosing adenomyosis, the presence of myometrial cysts was the most specific 2D-TVS feature (specificity, 98%; accuracy, 78%) and heterogeneous myometrium was the most sensitive (sensitivity, 88%; accuracy, 75%). The 3D-TVS markers JZdif ≥ 4 mm and JZ infiltration and distortion had high sensitivity (88%) and the best accuracy (85% and 82%, respectively). For 2D-TVS and 3D-TVS, respectively, the overall accuracy for diagnosis of adenomyosis was 83% and 89%, the sensitivity was 75% and 91%, the specificity was 90% and 88%, the positive predictive value was 86% and 85% and the negative predictive value was 82% and 92%. CONCLUSIONS: The coronal section of the uterus obtained by 3D-TVS permits accurate evaluation and measurement of the JZ, and its alteration has good diagnostic accuracy for adenomyosis.