Diagnostic value of delineating deep fascia in distinguishing between benign and malignant soft‐tissue tumors in lower limbs using 3.0 T magnetic resonance imaging

PURPOSE: To determine the association between morphological changes to the deep fascia and the malignancy of soft-tissue tumors in the lower limbs using 3.0 T magnetic resonance imaging (MRI). MATERIALS AND METHODS: MR images of 47 consecutive patients with 48 pathologically proven soft-tissue tumors in the lower limbs were retrospectively reviewed by two radiologists. Lesions were divided into four groups according to their predominant location relative to the deep fascia: Group A: subcutaneous lesions superficial to the deep fascia (n = 9); Group B: lesions located beneath the deep fascia (n = 8); Group C: lesions centered in the interspaces of the deep fascia investment (n = 11); and Group D: intramuscular lesions (n = 20). RESULTS: The deep fascial structures were complete in all of the 19 benign lesions. In malignant lesions, destruction signs of the deep fascia were observed in 27 of the 29, which were characterized by disappearance/disruption of the fascial line and aggressive growth penetrating through the fascial line into the adjacent compartment, or disappearance/disruption of the intermuscular septa and embedding the mutilated fascial septa within the lesion, or destruction of the fascia-muscle planes and abolishment of the deep fascial interspaces. Diagnosis of malignancy based on the signs of destruction of the deep fascial structure delineated with 3.0 T MRI, the sensitivity, specificity, and accuracy were 93.10%, 100%, and 95.83%, respectively. CONCLUSION: Tumor involvement and destruction of the deep fascial structures visualized by 3.0 T MRI may be of utility in differentiating malignant from benign soft-tissue tumors.