Imaging Appearances of the Most Common Malignant and Benign Lesions from a Regional Soft Tissue Sarcoma Diagnostic Center

Purpose or Learning Objective: Soft tissue palpable lesions are a frequent concern for patients. Although rare, soft tissue sarcoma can be highly aggressive, with resectability and overall survival rates correlated with early recognition and diagnosis. The appearance of soft tissue lesions can vary on ultrasonography (US) and magnetic resonance imaging (MRI). Histologic analysis is the gold-standard investigation. We present the imaging findings of the most common benign and malignant soft tissue lesions collected from a regional soft tissue sarcoma diagnostic center. Methods or Background: A retrospective single-center analysis was performed of 261 patients who underwent a US-guided core biopsy after being referred via a 2-week wait pathway to a regional soft tissue sarcoma diagnostic center. Histologic findings were graded benign (185 [71%]) and malignant (76 [29%]) with further histologic tumor subtypes provided. Comparison was made with both the US and MRI appearances of the most common benign and malignant tumor subtypes. Results or Findings: Of the 185 benign soft tissue lesions biopsied, the most common histologic subtypes were benign cutaneous lesions (37), benign vascular lesions (12), and benign fibrous lesions (21). Of the 76 malignant soft tissue lesions biopsied, the most common subtypes were sarcoma (36), skin malignancy (17), and lymphoma (17). We present the MRI appearances of these tumors and demonstrate key distinguishing factors: depth, size, T2-weighted image signal intensity, heterogeneity, and contrast enhancement. Conclusion: The imaging appearances of benign and malignant soft tissue lesions can present a diagnostic challenge for radiologists, but correct early identification can improve resource use and patient experience. Knowledge of typical malignant features can prompt early biopsy and diagnosis. Similarly, if a typically benign lesion is identified, the clinician can reassure the patient, who can potentially avoid an unnecessary confirmation with a core biopsy. Publication History Article published online: 26 May 2023 © 2023. Thieme. All rights reserved. Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA