Liposarcoma is one of the most common malignant soft tissue tumors in adults, accounting for about 10% of soft tissue sarcomas. Histologically, they are classified into five types: highly differentiated, dedifferentiated, mucinous, round cell, and pleomorphic, whereas they can be classified into three major categories based on their cellular and molecular biological features: highly differentiated and dedifferentiated, mucinous round cell, and pleomorphic liposarcomas;

It is difficult to differentiate hyperdifferentiated from benign adipose tumors and dedifferentiated from malignant spindle-shaped pleomorphic undifferentiated tumors. Studies have confirmed that highly differentiated dedifferentiated liposarcomas have characteristic ring and/or giant marker chromosomes, all with amplification of the 12q13-15 region;

The FRS2 gene (Fibroblast growth factor receptor substrate 2) is located in the 12q13-15 region, and FRS2 gene status combined with MDM2 gene and CDK4 gene status is a common abnormality in highly differentiated liposarcoma.