Abstract
ObjectivesTo compare magnetic resonance imaging (MRI) parameters of small, deeply located non-malignant and malignant soft-tissue tumors (STTs).MethodsBetween May 2011 and December 2017, 95 MRIs in 95 patients with pathologically proven STTs of small size (<5 cm) and deep location (66 non-malignant and 29 malignant) were identified. For qualitative parameters, consensus reading was performed by three radiologists for presence of necrosis, infiltration, lobulation, and the tail sign. Apparent diffusion coefficient (ADC) was analyzed by two other radiologists independently. Univariable and multivariable analyses were performed to determine the diagnostic performances of MRI parameters in differentiating non-malignancy and malignancy, and for non-myxoid, non-hemosiderin STTs and myxoid STTs as subgroups. Interobserver agreement for ADC measurement was calculated with the intraclass correlation coefficient.ResultsInterobserver agreement on ADC measurement was almost perfect. On univariable analysis, the malignant group showed a significantly larger size, lower ADC, and higher incidence of all qualitative MRI parameters for all STTs. Size (p = 0.012, odds ratio [OR] 2.57), ADC (p = 0.041, OR 3.85), and the tail sign (p = 0.009, OR 6.47) were independently significant on multivariable analysis. For non-myxoid, non-hemosiderin STTs, age, size, ADC, frequency of infiltration, lobulation, and the tail sign showed significant differences between non-malignancy and malignancy on univariable analysis. Only ADC (p = 0.032, OR 142.86) retained its independence on multivariable analysis. For myxoid STTs, only size and tail sign were significant on univariable analysis without independent significance.ConclusionsSize, ADC, and incidence of qualitative MRI parameters were significantly different between small, deeply located non-malignant and malignant STTs. Only ADC was independently significant for both overall analysis and the non-myxoid, non-hemosiderin subgroup.
Highlights
Soft-tissue tumors (STTs) of musculoskeletal regions are a common indication for evaluation by imaging
Diagnosis with proper management of malignant soft-tissue tumors (STTs) leads to a better prognosis for patients [13], so it is desirable to identify imaging findings that can aid in appropriate radiologic diagnosis of these lesions
Magnetic resonance imaging (MRI) plays an important role in determining the histopathologic nature of STTs, non-malignant and malignant STTs show overlapping MRI features [8,9,10,11,12]
Summary
Soft-tissue tumors (STTs) of musculoskeletal regions are a common indication for evaluation by imaging. Characterizing STTs with regard to their histopathologic nature–whether they are benign or malignant–based on imaging studies is crucial in the management of these lesions, and for suggesting the clinical step, including biopsy. Several reports have recommended biopsy for STTs with a diameter larger than 5 cm, deep location, and interval growth, or when a definitive diagnosis cannot be made with imaging studies; currently, there are no established indications for STT biopsy [1,2,3,4]. Magnetic resonance imaging (MRI), with its excellent soft-tissue contrast and large field of view, plays a substantial role in assessment of STTs. Several MRI features are helpful in differentiating benign and malignant STTs [5,6,7]. Diagnosis with proper management of malignant STTs leads to a better prognosis for patients [13], so it is desirable to identify imaging findings that can aid in appropriate radiologic diagnosis of these lesions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
