Myxoid Liposarcoma : Introduction

Introduction: Myxoid liposarcoma (LPS) is the 2nd most common type of LPS and accounts for 30-50% of all LPS. It has a predilection for lower extremities. This entity includes:

• low-grade, highly differentiated myxoid tumor with uniform spindle/stellate cells, lipoblasts, plexiform capillary network and a relatively good prognosis; the prototypic myxoid liposarcoma (left panel)
• hypercellular, high-grade tumor with little to no lipoblastic differentiation and worse prognosis; previously referred to as round cell liposarcoma (right panel)

These two subtypes represent the two prognostic ends of the same tumor as they share clinical, epidemiological, cytogenetic, and molecular pathogenetic features (translocations involving chromosome 12 resulting in FUS-DDIT3 fusion (most often) or EWSR1-DDIT3 fusion (rare).