Dedifferentiated Liposarcoma
Supplemental Studies
Immunohistology
Stains on dedifferentiated component
| Marker |
% of Tumors Reported Positive |
| p16 |
78-97% |
| MDM2 |
55-95% |
| CDK4 |
84-92% |
| CD34 |
25% |
| Desmin |
44% |
| Smooth muscle actin |
44% |
| Neurofilament |
41% |
| S100 |
9% |
| Muscle specific actin |
6% |
| Keratin |
3% |
- MDM2 and CDK4 are markers amplified as a result of the supernumerary ring chromosomes described below
Immunohistochemistry of lipomatous tumors
Genetic analysis
-
Frequently exhibits same findings as atypical lipomatous tumor
-
>60% have supernumerary ring chromosomes derived from 12q(13-15)
- 16q13 abnormality rare
- Common in spindle cell and pleomorphic lipomas
- Karyotype is typically less complex than other non-fatty sarcomas
FISH/PCR of lipomatous tumors
Spindle cell / pleomorphic lipoma showed 89% chromosome 12 polysomy
