The study included 150 women with adnexal lesion who underwent surgical intervention. The ultrasound findings were recorded as per O’RADS classification and O’RADS categories were tested for accuracy against histopathology.

·       The study cohort had women aged 12- 72years with the mean age of 35.89 years.

·       63 (42%) of women had normal BMI and 87 (58%) women had BMI >25 kg/m².

·       There were 83 (55.3%) participants who were nulliparous and 67 (44.7%) were multiparous.

·       Nearly one-third {43 (28.7%)} of the participants had history of infertility. 28 (18.7%) women were known case of endometriosis and 22 (14.7%) were postmenopausal.

·       There were 50 (33.3%) women who were co morbid and 5 (3.3%) had family history of cancer.

·       Out of 150, 131 (87.3%) were non-malignant and 19 were malignant (12.7%) which included 6 borderline tumours.

·       O’RADS category 2 (benign) had 74 cases and 100% were benign, category 3 (low risk) had 32 cases in which only 1 (3.1%) was malignant, category 4 (intermediate risk) had 38 cases in which 12 (31.6%) were malignant and category 5 had 6 cases and 100% were malignant.

·       Among the ultrasound parameters, features significantly associated with malignancy were colour score, ascites, solid areas, inner margins and number of papillary projections.

·       O’RADS 4 had the highest false positive cases among all categories. Ultrasound parameters resulting in maximum false positives were number of locule, solid areas and number of papillary projections.

·       Taking O’RADS 4 as the appropriate cutoff for malignancy, the diagnostic accuracy of O’RADS was 82.7% with sensitivity of 94.7% and specificity of 80.9%.

·       Statistically significant relationship was seen between O’RADS risk of malignancy and final impression. (p <0.001).