Dedifferentiated Liposarcoma : Immunohistochemistry

Comments:
Immunohistochemical Profile: Like atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL), there is amplification of CDK4 and MDM2 in the vast majority of dedifferentiated liposarcomas (DLPS) which can be detected by immunohistochemistry. CDK4 and MDM2 markers are useful in separating DLPS from pleomorphic liposarcoma and non-lipomatous high-grade sarcomas.

The staining is limited to the nuclei of atypical stromal cells and the number of positive cells is variable. Positive staining may be detected focally (false positive) in a small percentage of spindle cell/pleomorphic lipomas, foamy macrophages in areas of fat necrosis, and occasional non-lipomatous sarcomas like malignant peripheral nerve sheath tumors.

DLPS with heterologous elements are positive for their respective immunohistochemical markers.