Low-grade fibromyxoid sarcoma of the small bowel mesentery: computed tomography and magnetic resonance imaging findings

Abstract

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor that commonly arises in the lower extremities but rarely in the mesentery. We report computed tomography (CT) and magnetic resonance imaging (MRI) findings of LGFMS of the small bowel mesentery. On CT, the mass was composed of two components. One component, on its right side, appeared to have isointense attenuation relative to muscle, whereas the other component, on its left side, appeared to have low attenuation. On MRI the mass on the right side showed hypointensity similar to muscle on both T1-and T2-weighted images as well as mostly slight enhancement on contrast-enhanced T1-weighted images. On the other hand, the mass on the left side showed relative hypointensity on T1-weighted images and hyperintensity on T2-weighted images as well as intense enhancement on contrast-enhanced T1-weighted images, suggesting that the tumor contained myxoid tissue. The myxoid area of LGFMS may have a tendency to reveal intense enhancement on contrast-enhanced images.

Haemorrhagic low-grade fibromyxoid sarcoma: MR findings in two young women

“…In case 1, the outer portion on fat-suppressed contrastenhanced T 1 weighted images appeared as multiple nodules, consistent with findings of multiple intralesional nodules in several previous reports [4,7,9,10]. Such nodules may be related to the alternating fibrous and myxoid areas in LGFMS.…”

“…The most common clinical presentation is a firm, slow-growing painless mass. Most tumours occur in the subcutaneous or deep soft tissues of the lower limbs, shoulders or thoracic wall with others in the axilla, groin, buttocks, neck, mesentery and retroperitoneum [1][2][3][4].…”

“…The degree of cellularity is low to moderate, mitotic figures are uncommon and nuclear pleomorphism is usually absent or slight. A prominent and rich capillary vascular network is commonly present in myxoid areas [4,5,7].…”

“…In general, fibrous tissue components appear hypointense on T 1 weighted and T 2 weighted images and show slight enhancement. Myxoid tissue components are hypointense on T 1 weighted images, hyperintense on T 2 weighted images and show variable enhancement on contrast-enhanced T 1 weighted images [2][3][4]7].…”

“…LGFMS can occur at various anatomical locations, including the superficial and deep soft-tissues of the proximal extremities, trunk, small bowel mesentery and intracranially, and frequently presents as a slow-growing, non-tender, firm tumour [1][2][3][4]. Recurrence and metastasis, usually to the lung, have been reported at variable but significant rates [1,5,6].…”