Diagnostic Accuracy of a Sonographic Scoring System in Predicting the Malignant Potential of a Soft-tissue Swelling

Soft-tissue masses usually present as painless palpable lumps. Although histopathologic examination (HPE) is diagnostic, ultrasonography (USG), being cost-effective, is the preferred screening modality. However, as it is operator dependent, the diagnostic accuracy might be affected. Thus, this study was planned to determine the diagnostic accuracy of USG with Doppler in identifying the malignant nature of soft-tissue swellings and also to develop a scoring system with a valid cutoff to help differentiate malignant lesions from the benign ones.

This analytical study with longitudinal design was conducted from July 2022 to June 2024 on patients with soft-tissue swelling selected by systematic random sampling. Data were collected by face-to-face interview, USG with Doppler, and histopathological examination. Data were presented with the help of descriptive and inferential statistics.

USG had 83.3% sensitivity, 89.5% specificity, 71.4% positive predictive value, 94.4% negative predictive value, and 88.0% accuracy in differentiating between benign and malignant soft-tissue swelling. The interrater reliability between USG and HPE indicated "substantial agreement" (Cohen's Kappa 0.689, P = 0.000). Using the scoring system, the swelling could be categorized into benign (score <3.50), indeterminate (score 3.50-6.50), and malignant (score ≥6.50).

USG with Doppler can accurately differentiate between benign and malignant soft-tissue swelling. USG with Doppler-based scoring system could increase the sensitivity and specificity of this imaging modality.