Myxoid liposarcoma explained

A myxoid liposarcoma is a malignant adipose tissue neoplasm^[1] of myxoid appearance histologically.

Myxoid liposarcomas are the second-most common type of liposarcoma, representing 30–40% of all liposarcomas in the limbs, occurring most commonly in the legs, particularly the thigh, followed by the buttocks, retroperitoneum, trunk, ankle, proximal limb girdle, head and neck, and wrist. They occur in the intermuscular fascial planes or deep-seated areas. They present as a large, slow-growing, painless mass.^[2]

The neoplastic cells in these neoplasms contain chromosomal translocations which create one of two fusion genes: the FUS-DDIT3 in ~90% and the EWSR1-DDIT3 fusion gene in up to 10% of myxoid liposarcoma cases.^[3] The FUS-DDIT3 fusion gene forms by a merger of part of the FUS FET gene family gene normally located at band 11.2 on the short (or "p") arm of chromosome 16 with part of the DDIT3 ETS transcription factor family gene normally located at band 13.3 on the long (or "q") arm of chromosome 12. This fusion gene is notated as t(12;16)(q13;p11).^{[4] [5]} Preclinical studies, i.e. laboratory studies, suggest that the FUS-DDIT3 fusion gene may act as an oncogene to promote the development of myxoid liposarmas.^[6] The EWSR1-DDIT3 fusion gene forms by a merger of the EWSR1 FET gene family gene located at band 12.2 on the q arm of chromosome 22 with part of the DDIT3 gene. This fusion gene is notated as t(12;22)(q13;12).^{[7] [8] [9]}

Additional images

See also

• Lipoma
• Trabectedin

External links

• Myxoid liposarcoma: a rare soft-tissue tumor with a misleading benign appearance
• Efficacy of first-line doxorubicin and ifosfamide in myxoid liposarcoma. 2012

Notes and References

1. Web site: Orphanet: Myxoid/round cell liposarcoma. Orpha.net. October 27, 2019.
2. Myxoid Liposarcoma: Appearance at MR Imaging with Histologic Correlation . 2000 . Sung . etal . 10.1148/radiographics.20.4.g00jl021007 . 10903690 . 20 . 4. RadioGraphics . 1007–1019.
3. Flucke U, van Noesel MM, Siozopoulou V, Creytens D, Tops BB, van Gorp JM, Hiemcke-Jiwa LS . EWSR1-The Most Common Rearranged Gene in Soft Tissue Lesions, Which Also Occurs in Different Bone Lesions: An Updated Review . Diagnostics (Basel, Switzerland) . 11 . 6 . June 2021 . 1093 . 34203801 . 8232650 . 10.3390/diagnostics11061093 . free .
4. Aman P . Rearrangement of the transcription factor gene CHOP in myxoid liposarcomas with t(12;16)(q13;p11) . Genes Chromosomes Cancer . 5 . 4 . 278–85 . 1993 . 1283316 . 10.1002/gcc.2870050403 . vanc. Ron D . Mandahl N . 3 . Fioretos . Thoas . Heim . Sverre . Arheden . Kristina . Willén . Helena . Rydholm . Anders . Mitelman . Felix . 1998665 .
5. Göransson M, Andersson MK, Forni C, etal . The myxoid liposarcoma FUS-DDIT3 fusion oncoprotein deregulates NF-kappaB target genes by interaction with NFKBIZ . Oncogene . 28 . 2 . 270–8 . January 2009 . 18850010 . 10.1038/onc.2008.378.
6. Owen I, Yee D, Wyne H, Perdikari TM, Johnson V, Smyth J, Kortum R, Fawzi NL, Shewmaker F . The oncogenic transcription factor FUS-CHOP can undergo nuclear liquid-liquid phase separation . Journal of Cell Science . 134 . 17 . September 2021 . 34357401 . 10.1242/jcs.258578 . 8445604 .
7. Rabbitts TH, Forster A, Larson R, Nathan P . Fusion of the dominant negative transcription regulator CHOP with a novel gene FUS by translocation t(12;16) in malignant liposarcoma . Nat. Genet. . 4 . 2 . 175–80 . 1993 . 7503811 . 10.1038/ng0693-175 . 5964293 .
8. Crozat A, Aman P, Mandahl N, Ron D . Fusion of CHOP to a novel RNA-binding protein in human myxoid liposarcoma . Nature . 363 . 6430 . 640–4 . 1993 . 8510758 . 10.1038/363640a0 . 1993Natur.363..640C . 4358184 .
9. Forni C, Minuzzo M, Virdis E, etal . Trabectedin (ET-743) promotes differentiation in myxoid liposarcoma tumors . Mol. Cancer Ther. . 8 . 2 . 449–57 . February 2009 . 19190116 . 10.1158/1535-7163.MCT-08-0848 . free .