Table of Contents
Epidemiology | Sites | Treatment | Microscopic (histologic) images | Molecular / cytogenetics description | Additional referencesCite this page: Myxoid / round cell liposarcoma - general. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueadiposemyxoidlipo.html. Accessed March 21st, 2023.
Epidemiology
- #2 most common subtype of liposarcoma (33 - 50% of cases), after well differentiated liposarcoma
- Adults in 20’s to 40’s
- Rare in children under 10 years
Sites
- Usually limb or thigh in muscle or deep tissue
- Almost never retroperitoneal, only rarely in subcutis
- Either well differentiated / low grade (well differentiated) or poorly differentiated / high grade (round cell)
Treatment
- Wide local excision, possibly radiotherapy (Cancer 2009;115:3254) or chemotherapy to prevent recurrence
- Poor prognostic factors include poorly differentiated (round cell) component, large size, necrosis, high Ki-67 (J Clin Pathol 2003;56:579), p53 overexpression (Clin Cancer Res 2001;7:3977)
- Has both pulmonary and extrapulmonary metastatic deposits; pulmonary metastatic lesions are usually high grade lesions (Sarcoma 2012;2012:345161)
- Patients with > 5% round cell component are at higher risk of local recurrence, metastasis and tumor-related death and should be considered for adjuvant radiotherapy and possibly chemotherapy (Sarcoma 2011;2011:538085)
Microscopic (histologic) images
Images hosted on other servers:
Various percentages of round cells
Comparison of low grade and high grade tumors
Molecular / cytogenetics description
- Associated with t(12;16)(q13;p11) - FUS-DDIT3 also called TLS-CHOP fusion gene in 90% (J Mol Diagn 2000;2:132)
- Less common is t(12;22)(q13;p11) - EWSR1-DDIT3 (Cancer Res 1995;55:24) or ins(12;16)(q13;p11.2p13) (Am J Clin Pathol 1997;108:35)
- Multifocal tumors may originate from same clone (Clin Cancer Res 2000;6:2788)
- Have immature adipogenic status (Hum Pathol 2009;40:1244)
Additional references
