EP23.16: Diagnostic accuracy of modified benign descriptor three in the diagnosis of simple cysts and cystadenomas

To evaluate the diagnostic accuracy of the modified benign descriptor three in the diagnosis of simple cysts and cystadenomas. Ambispective observational study based on ultrasound data collected at a University Hospital with a gynecologic oncology unit between 2012 and 2023. Two IOTA-certified level III gynecologists classified adnexal masses using the MBD. The main result was the correct classification of simple cysts and cystadenomas, based on the third descriptor of the MBD (MBD 3). Histopathology was used as the diagnostic reference standard. A diagnostic accuracy study was performed. A total of 1,047 adnexal masses were assessed, of which 656 (62.6%) were included when they met the classification criteria for their evaluation based on MBD. 156 masses were diagnosed as simple cysts and cystadenomas by the MBD 3, of which 133 (85.3%) corresponded to simple cysts and cystadenomas by histopathology. 14.7% (23/156) were false negatives, and the diagnoses that caused confusion were: 69.6% hemorrhagic cysts, 13.2% cysts with inflammation, 4.3% Rete ovarii cyst, 4.3% Mature cystic teratoma, 4.3% Metastatic involvement of low-grade mucinous neoplasia, and 4.3% adnexal torsion. The diagnostic yield for MBD 3 had a sensitivity of 74.7%, specificity of 95.2%, positive predictive value of 85.3%, negative predictive value of 91%, and diagnostic accuracy of 89.6%. In our experience, MBD 3 has an adequate diagnostic performance for characterising cystadenomas and simple cysts. Our findings are consistent with those reported in the literature.