IOTA Simple Ultrasound Rules for Triage of Adnexal Mass

Introduction: Adnexal mass affects younger population more often, the prevalence of these masses in the range of 0.17%–5.9% in asymptomatic women and 7.1%– 12% in symptomatic women. As these masses presents with very non-specific symptoms the differential diagnosis can include a long list of diseases ranging from benign conditions all the way to malignancies. The IOTA group also developed ‘Simple Rules’ that may be applied to a mass based on the presence or absence of five benign and five malignant ultrasound features. So, this study was performed to establish the diagnostic utility of these rules diagnosing ovarian malignancy. Aims and objectives: (a) To assess the ability of simple ultrasound rules to discriminate adnexal masses as benign or malignant. (b) To calculate the diagnostic accuracy of simple ultrasound rules from IOTA in diagnosing benign and malignant adnexal masses when compared against histopathology results. Material and methods: It was a cross-sectional observational study conducted from October 2019 till October 2021 in Department of Obstetrics and Gynecology, MKCG Medical College and Hospital, Berhampur, Odisha; India over 100 consecutive patients basing on following inclusion and exclusion criteria. Clinical information like chief complaints, menstrual history, and obstetric history, history of past illness and personal history were noted followed by per speculum, per vaginal and per rectal examination. Tumor markers like CA-125 were ordered for all patients after ultrasonography. IOTA classification done for all cases and placed for surgery as required. Histopathological examination was sent for the resected adnexal mass following surgery. Results: Majority of cases i.e., 66 cases (66%) were in the age group of 20 to 40 years. Out of 100 cases, 81 cases (81%) were pre-menopausal, and 19 cases (19%) were post-menopausal. The most common presenting complaint was abdominal pain in 52 cases (52%) followed by abdominal mass in 27 cases (27%) and abnormal vaginal bleeding in 3 cases (3%). Nonspecific complaints were presented in 18 cases (18%). Based on IOTA simple rules, in 92 patients (92%), multiple features in combination were found among which B-5 was the most common presentation in benign conditions in 68% of cases, while M-4 was the most common among malignant conditions in 22% of cases. Out of all cases studied, 77 cases (77%) of the patients had benign lesions and rest 23 cases (23%) had malignant lesions. Among benign lesions, serous cystadenoma in 25 cases (25%) was the most common. Among the malignant lesions, serous cystadenocarcinoma was the most common. The overall diagnostic accuracy of CA-125 was of 84.5 % and overall diagnostic accuracy of RMI scoring was 85 %. The overall diagnostic accuracy of IOTA simple rule for adnexal mass was 86%. Conclusion: This overall diagnostic accuracy of IOTA simple rule was higher than that of CA-125 and RMI. IOTA simple rules have good sensitivity and specificity for identifying malignant adnexal masses and differentiating benign from malignant.