Accuracy of Ultrasound Imaging Findings in Diagnosis of Adnexal Masses: A Cross-sectional Study

Abstract

Introduction: Adnexal mass lesions are common among women of all age groups. Precise preoperative estimation of the benign or malignant nature of an adnexal mass is important to avoid additional surgical treatment. Sonography is the initial imaging study of choice in the evaluation of women with suspected adnexal masses. Assiut scoring model is a simpler model for differentiation of adnexal masses into benign and malignant using various ultrasonographic parameters. Aim: To assess the accuracy of ultrasound in differentiating benign from malignant adnexal masses using Assiut scoring model. Materials and Methods: This cross-sectional study was conducted in Department of Radiodiagnosis at Christian Medical College and hospital (tertiary care hospital), Ludhiana, Punjab, India, from November 2018 to January 2021. The study included 80 cases of adnexal masses. An Ultrasound (USG) diagnosis was made based on tumour volume, type of mass, papillary projections, septae and vessel location and Assiut score was obtained. Histopathological examination was carried out following surgery or biopsy. The diagnostic accuracy of USG (with histopathology as gold standard) was determined. Sensitivity, specificity, positive predictive value and negative predictive value of USG was assessed for predicting malignancy taking histopathology as gold standard. The p-value <0.05 was considered statistically significant. Results: Most numbers of patients (33 patients, 41.25%) belonged to age group 21-30 years. Mean age of study subjects was 35.35±12.8 years. Majority (60, 75%) of patients were benign and 20 (25%) were malignant. The USG findings showed good agreement with histopathology (kappa=0.76, p-value<0.0001). Sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for correctly predicting malignant lesions being 90%, 90%, 75% and 96.43% respectively. Median Assiut score in malignant was significantly higher as compared to benign (9.95 vs 3.47, p-value<0.0001). Characteristics such as central or septal vascularization, presence of thick septa, papillary projections, multilocularity and high tumour volume (especially above 500 mL) showed a significant association with malignancy (p-value<0.0001). Conclusion: The USG based Assuit scoring model is a good tool in differentiating benign from malignant adnexal masses with high sensitivity and specificity.