Differentiation of benign and malignant superficial soft tissue lesions using real-time strain elastography

Abstract

To evaluate benign and malignant cutaneous-subcutaneous lesions using realtime strain elastography (RTSE) and to compare the findings with histopathologic results.Material Methods: Over a period of 10 months, 72 patients (38 with benign and 34 with malignant cutaneous and subcutaneous lesions) were prospectively included in this study. Elasticity patterns and strain ratios were examined for each lesion. Lesions were evaluated in 4 groups as yellow-red (soft; pattern-1), green-yellow (moderate; pattern-2), blue-green (hard; pattern-3) and blue (hardest; pattern-4). The stiffness of the lesions was displayed with strain ratios by comparing of a nearby reference tissue. The recorded images were compared with histopathologic findings.Results: On sonoelastograms, considering patterns 1-2 as benign and patterns 3-4 as malignant, the sensitivity, specificity, and positive and negative predictive values for the differentiation of malignant from benign lesions were 100%, 68.5%, 74%, and 100%, respectively. Considering a cut-off value of the strain ratio as >3.05, the sensitivity, specificity, and positive and negative predictive values were 91%, 89%, 88%, and 92%, respectively. The Area Under the Curve (AUC: 0.972) showed the excellent ability of strain elastography to differentiate benign and malignant lesions.Conclusions: RTSE is an important imaging tool to differentiate benign and malignant superficial soft tissue lesions. Our results suggest that RTSE can be used to predict malignancy since malignant lesions are more confidentially diagnosed than benign superficial soft tissue lesions on elastograms.

Practical approach to ultrasound of soft tissue tumors and the added value of MRI: how I do it

“…This modest discriminatory ability of elastography in part reflects the tissue heterogeneity of sarcomas. Conversely, carcinomas tend to have a more uniform tissue composition than sarcomas, and, as such, strain elastography is accurate at discriminating cutaneous carcinomas (squamous and basal cell carcinoma) from benign cutaneous lesions (such as seborrhoeic keratosis, actinic keratosis, keloid scar, pilar cyst, epidermoid cyst) with a strain ratio of value of >3.0 indicating malignancy (22,23) . An alternative strain elastography measure, known as the elasticity/ B-mode ratio (E/B ratio), may prove to be more helpful in discriminating malignant from benign soft tissue tumors (18) .…”