Dedifferentiated liposarcoma of the musculoskeletal system: expanded MR imaging spectrum from predominant fatty mass to non-fatty mass. (November 2019)

• Record Type: Journal Article
• Authors: Yun, Jae Sung; Chung, Hye Won; Song, Joon Seon; Lee, Sang Hoon; Lee, Min Hee; Shin, Myung Jin
• Is Part Of: Acta radiologica. Volume 60:Number 11(2019)
• Page Start: 1474
• Page End: 1481
• Publication Date: 2019-11
• Subjects: Dedifferentiated liposarcoma -- MDM2 -- CDK4 -- immunohistochemical staining -- non-fatty tumor -- MR; Radiology, Medical -- Periodicals; Radiography, Medical -- Periodicals; Radiotherapy -- Periodicals; 616.0757
• DOI: 10.1177/0284185119833060
• Languages: English
• ISSNs: 0284-1851

Abstract

Background: The morphology of musculoskeletal dedifferentiated liposarcoma was previously reported as well-defined non-lipomatous masses juxtaposed with fatty tumors. Purpose: To establish a new spectrum of magnetic resonance imaging (MRI) findings for dedifferentiated liposarcoma according to the quantity and distribution of the non-fatty component in the tumor. Material and Methods: This study consisted of a retrospective review of MRI of 14 patients with a total of 18 histopathologically proven dedifferentiated liposarcoma lesions in the musculoskeletal area. Tumors were classified into four categories (I–IV) according to MR features: I = a well-defined fatty mass and juxtaposed well-defined non-fatty mass; II = a non-fatty component within a predominant fatty mass; III = a focal fatty component within a large non-fatty mass; and IV = a non-fatty mass. Tumor size and depth were also analyzed. Results: The MR categorizations of the tumors were as follows: Category I, n = 3; Category II, n = 1; Category III, n = 7; and Category IV, n = 7. The mean tumor size was 11.9 cm (range = 5.0–22.2 cm). Most of the tumors showed a predominant non-fatty area and were deeply located at the intra- or intermuscular space. Conclusion: Dedifferentiated liposarcoma lesions showed a diverse spectrum of MRI findings. Although the presence of a non-fatty region within or adjacent to a well-defined fatty mass can suggest dedifferentiated liposarcoma, non-fatty masses without a fatty component were frequent on MRI.