Comparative Ultrasonographic Evaluation of Morphology and Vascularization in Endometriomas and Ovarian Mature Cystic Teratomas

<b>Background/Objectives</b>: Adnexal masses are commonly encountered in the routine practice of gynecologists, and transvaginal ultrasonography is the preferred imaging modality for assessing the masses in size and complexity. There has been a notable lack of focus on comparative studies concerning benign adnexal tumors. This study aimed to define and compare the specific morphological and vascular characteristics of ovarian mature cystic teratomas (MCTs) and endometriomas using transvaginal ultrasound and Doppler analysis. <b>Methods</b>: This retrospective analysis included 93 patients who underwent surgical intervention for benign adnexal masses at the Obstetrics and Gynecology Clinic Narodni Front from 1 January 2020 to 1 January 2022. Morphological parameters included the appearance of tumors, the largest diameter, volume, capsule thickness, and the presence of fluid in the pouch of Douglas. Hemodynamic parameters included the localization and quantity of blood vessels within the mass, Resistance Index (RI), peak systolic velocity (Vmax), and end-diastolic velocity (Vmin) within detectable tumor vessels. Flow was also assessed in the uterine arteries, calculating the AURI (uterine artery RI) on both the tumor and contralateral sides. <b>Results</b>: There were 46 patients with ovarian mature cystic teratomas, as well as 46 patients with endometriomas; 1 patient presented with both tumors. There were significant differences in ultrasonographic morphological appearance between the two groups. MCTs most frequently presented as multilocular solid cysts (51.0%) or unilocular solid cysts with hyperechoic content (20.4%). Conversely, the majority of endometriomas were classified as unilocular cysts with ground-glass echogenicity (45.5%). A significant difference was identified in the RI of intracystic vessels and the RI of the ipsilateral uterine artery (AURI). Endometriomas presented elevated RI values (0.57 vs. 0.54, <i>p</i> = 0.04) and reduced AURI (0.81 vs. 0.83, <i>p</i> = 0.02) compared to teratomas. <b>Conclusions</b>: These findings confirm that specific morphological and Doppler parameters, particularly the RI and AURI, can assist in distinguishing between endometriomas and mature cystic teratomas. This suggests a potential role for Doppler analysis in improving diagnostic precision for common benign adnexal tumors in clinical practice.