Undiff. Pleomorphic Sarcocma : Inflammatory
Undifferentiated Pleomorphic Sarcoma (UPS), Inflammatory Type: Some cases of UPS arising in the retroperitoneum show a prominent inflammatory component consisting of xanthoma cells, neutrophils, lymphocytes or plasma cells. There were previously referred to as inflammatory MFH. Most cases are examples of dedifferentiated liposarcoma and will show MDM2 amplification. The neoplastic cells are often seen phagocytizing neutrophils. The inflammatory areas usually transition to conventional storiform pattern. Clinically, inflammatory UPS is frequently associated with paraneoplastic signs and symptoms such as anorexia, weight loss, fever, and leukocytosis. This is secondary to production of tumor necrosis factor, IL-6 and IL-8 by the tumor. The symptoms disappear after tumor removal.