Diagnostic value of tumor-fascia relationship in superficial soft tissue masses on magnetic resonance imaging

Abstract

Purpose: Many surgeons participate in the management of superficial soft tissue masses, and a preoperative incorrect diagnosis frequently results in dismal oncological outcomes. The aim of this study was to identify distinguishing magnetic resonance imaging features between malignant and non-malignant lesions.

Methods: The clinicopathological data for 219 patients (men 114; women 105) with superficial soft tissue masses treated from January 2007 to December 2016 in our institution were retrospectively analyzed. The median age at the first visit was 55.6 years (range 1-90 years). MRI findings of tumor size, margin, lobulation, intratumoral hemorrhage, peritumoral edema, and tumor-fascia relationship were compared with the final histological diagnosis and tumor grade.

Results: Univariate analysis revealed significant relationships between histologically malignant lesions and tumor size ≥5 cm (p = 0.035), positive peritumoral edema (p = 0.031), and tumor-fascia relationship (p<0.001), but not margin (p = 0.107), lobulation (p = 0.071), and intratumoral hemorrhage (p = 0.17). In addition, using multivariate analysis, the tumor-fascia relationship (p<0.001) and tumor size were significant factors. A significant correlation between tumor-fascia relationship and malignancy (p<0.001) was observed; such a relationship was, however, not observed for tumor grade (p = 0.43).

Conclusions: Tumors measuring ≥5 cm and the tumor-fascia relationship on magnetic resonance imaging are highly indicative of malignancy. When superficial soft tissue masses cross the superficial fascia and form obtuse angles with the fascia, sarcoma should be considered. The tumor-fascia relationship can offer surgeons useful information regarding the status of superficial soft tissue masses.

Fig 1. Magnetic resonance imaging findings of a superficial mass of the right lower leg in a 41-year-old woman.

Axial T1-weighted (a) and T2-weighted (b) images showing that the lesion did not contact the superficial fascia (Group 1 per the Galant classification). Pathologic examination of the resected specimen confirmed angioleiomyoma (c; hematoxylin-eosin staining; magnification ×200).

Fig 2. Magnetic resonance imaging findings of a superficial mass in the anterior part of the right lower leg in a 78-year-old woman.

Axial T1-weighted image showing a well-defined lesion with wider contact with the fascia at obtuse angles (a; Group 4 per the Galant classification). Pathologic examination of the resected specimen confirmed low-grade fibromyxoid sarcoma (b; hematoxylin-eosin staining; magnification ×200).