MDM2 gene is associated with which tumor?

• A. Osteosarcoma
• B. Liposarcoma
• C. Angiosarcoma
• D. Leiomyosarcoma

Answer: (B)

MDM2 amplification is a diagnostic hallmark of liposarcoma, especially the well-differentiated and dedifferentiated subtypes. The MDM2 gene (on chromosome 12q15) encodes a protein that inhibits p53, and in these liposarcoma forms the gene is amplified, creating a characteristic molecular signature often seen together with CDK4 amplification. This molecular pattern helps distinguish liposarcoma from benign lipomas and from other sarcomas, guiding accurate diagnosis. Detection is typically via FISH or other DNA-based assays for gene amplification, rather than relying on immunohistochemistry alone, which can be less specific. Other listed sarcomas do not characteristically exhibit MDM2 amplification as a defining feature. The best answer is liposarcoma.