Soft Tissue Sarcoma: The Important Role of Initial MRI Reports for Disease Control

Objectives Soft tissue sarcoma (STS) are a rare subtype of soft tissue masses, representing less than 1% of all malignancies and are frequently misinterpreted as benign tissue lesions. This can lead to omission of biopsies or surgery at all, to unplanned or incomplete excisions and therefore to inadequate oncologic therapy In cases of suspicious soft tissue masses, magnetic resonance imaging (MRI) is the primary recommended type of diagnostics. We established a list of report characteristics which we would rate as crucially important to be able to follow good clinical practice. In this study, we evaluate whether these requirements were matched in radiologic reports for patients who were treated for STS in our clinic. Methods 1107 patients, who presented to our clinic in years 2012-2018, were evaluated. Patients with histopathological results of malignant STS were analyzed for the following characteristics (n = 126): Was the soft tissue mass adequately detected and described as anomalous? Is a conclusion drawn regarding the specific suspected diagnosis, i.e. type of soft tissue mass? Does the report mention a suspected malignancy or signs thereof? Does the report include a recommendation for a biopsy and histopathological analysis? Is a referral to a specialized sarcoma center recommended? Furthermore, we compared the initial radiologically suspected diagnosis to the final histopathological result to detect apparent mismatches. Results and Conclusion In all 126 cases of malign STS, the report recognized and described the mass in its correct localization and to full extent (100%). 86 of 126 reports raised concern that the mass shows signs of malignancy (68%). The majority of reports (n = 109, 87%) arrived at a tentative diagnosis. 32 of these tentative diagnoses showed a mismatch to the ultimate diagnoses. In 5 cases suspected type of malignancy was different to the final result. 27 reports had a gross misinterpretation of the masses as benign (20%) despite being malign. There was no correlation between mass size and likelihood of misinterpretation as benign. 38 reports suggested to obtain a biopsy of the mass for further analysis (30%). Only 7 reports recommended a referral to a sarcoma center for further diagnostics and/or treatment (6%). There was strong incoherence regarding the conducted MRI sequences. While most reports were based on at least one T1-weighed and one T2-weighed sequences, there was no common ground regarding the use of contrast agent or included planes. MRI report criteria showed unsatisfying incoherence, which puts patients at risk for inadequate treatment. To the authors opinion, MRI reports should not list a tentative diagnosis but signs of malignancies and recommend histopathological evaluation after a biopsy in a specialized sarcoma center. Standardization is impeded through the variation in obtained MRI sequences. Therefore, a common MRI protocol for soft tissue mass detection is inevitable to ensure the best possible care for affected patients. Stichwörter soft tissue sarcoma, unplanned excision, biopsy, MRI, sarcoma center Publication History Article published online: 15 October 2020 © 2020. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany