Myxoid Liposarcoma
Supplemental Studies
Immunohistology
- S100 stains mature fat cells and lipoblasts but is rarely of diagnostic use
- CD34 negative or stains rare small cells
- MDM2 and CDK4 generally negative
MDM2 | CDK4 | p16 | |
Atypical lipomatous tumor | 45-100% | 84-92% | 78-97% |
Dedifferentiated liposarcoma | 55-95 | 90-100 | 90 |
Myxoid / round cell liposarcoma | 0-4 | 0-4 | 0 |
Pleomorphic liposarcoma | 0 | 0 | 0 |
Lipoma | 0-4 | 0-2 | 0 |
Spindle cell and pleomorphic lipoma | 0-25 | 0-6 | 20 |
Angiomyolipoma | 0 | 0 | |
Hibernoma | 0 | 0 | positive, variable |
Lipoblastoma | 0 (1 case) | 0 (1 case) | positive (1 case) |
Genetic analysis
- FUS/CHOP t(12;16)(q13;p11) in 90% of cases
- EWS/CHOP t(12;22)(q13;q12) in remainder
MDM2 FISH | MDM2 QPCR | CDK4 FISH | CDK4 QPCR | |
Atypical lipomatous tumor | 90-100% | 72-100% | 75-100% | 69-100% |
Dedifferentiated liposarcoma | 100% | 100% | 100% | 100% |
Myxoid liposarcoma | 20% | |||
Spindle cell / pleomorphic lipoma | Negative | Negative | Negative | Negative |
Angiolipoma | Negative | |||
Lipoma, NOS | Negative | Negative | Negative | Negative |
Sarcomas | 0-40% | 0% | 0% | 0% |