Research Article
A Prospective Observational Study Comparing IOTA Simple Ultrasound Rules and RMI-2 Scoring System in Correlation with Histopathological Examination in Diagnosing Adnexal Masses at a Tertiary Care Centre
Sayantani Bhattacharyya and Falguni Patel*
Department of Obstetrics and Gynaecology, Government Medical College, Surat, Gujarat, India.
*Corresponding author:Falguni Patel, Department of Obstetrics and Gynaecology, Government Medical College, Surat, Gujarat, India. E-mail id: shivshakti12.patel@gmail.com
Article Information:Submission: 02/04/2026; Accepted: 12/05/2026; Published: 15/05/2026
Abstract
Background: Adnexal masses are frequently encountered in gynecological practice and often present a diagnostic challenge in differentiating benign from malignant lesions before surgery. Accurate preoperative assessment is essential for appropriate referral, surgical planning, and improving patient outcomes. The International Ovarian Tumor Analysis (IOTA) Simple Ultrasound Rules and Risk of Malignancy Index-2 (RMI-2) are commonly used tools for this purpose.
Objectives: To compare the diagnostic accuracy of IOTA Simple Ultrasound Rules and RMI-2 scoring system in differentiating benign and malignant adnexal masses, using histopathological examination as the gold standard. Methods: This prospective study included 50 women with adnexal masses at a tertiary care centre. Patients underwent clinical evaluation, ultrasonography, serum CA-125 testing, and assessment by IOTA Simple Rules and RMI-2, with final diagnosis confirmed by histopathology. Diagnostic performance was compared using sensitivity, specificity, PPV, and NPV.
Results: IOTA Simple Rules demonstrated 100% sensitivity, 96.8% specificity, 93.75% PPV, and 100% NPV. RMI-2 showed 81.25% sensitivity, 79.4% specificity, 65% PPV, and 90% NPV. IOTA Simple Rules showed superior diagnostic performance compared to RMI-2 in differentiating benign from malignant adnexal masses.
Conclusion: IOTA Simple Ultrasound Rules are more accurate than RMI-2 in the preoperative evaluation of adnexal masses and can be used as a simple, reliable, and effective screening tool in routine gynecological practice.
Objectives: To compare the diagnostic accuracy of IOTA Simple Ultrasound Rules and RMI-2 scoring system in differentiating benign and malignant adnexal masses, using histopathological examination as the gold standard. Methods: This prospective study included 50 women with adnexal masses at a tertiary care centre. Patients underwent clinical evaluation, ultrasonography, serum CA-125 testing, and assessment by IOTA Simple Rules and RMI-2, with final diagnosis confirmed by histopathology. Diagnostic performance was compared using sensitivity, specificity, PPV, and NPV.
Results: IOTA Simple Rules demonstrated 100% sensitivity, 96.8% specificity, 93.75% PPV, and 100% NPV. RMI-2 showed 81.25% sensitivity, 79.4% specificity, 65% PPV, and 90% NPV. IOTA Simple Rules showed superior diagnostic performance compared to RMI-2 in differentiating benign from malignant adnexal masses.
Conclusion: IOTA Simple Ultrasound Rules are more accurate than RMI-2 in the preoperative evaluation of adnexal masses and can be used as a simple, reliable, and effective screening tool in routine gynecological practice.
Keywords:Adnexal mass; IOTA; RMI-2; Ovarian malignancy; Ultrasonography; Histopathology; CA-125