Liposarcoma : WHO Classification

The WHO Classification of liposarcoma includes: atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL), myxoid/round cell liposarcoma, dedifferentiated liposarcoma (DLPS), and pleomorphic liposarcoma.

• ALT/WDL and DLPS are the most common subtypes and together they represent 60% of all liposarcomas. ALT/WDL is a low-grade, indolent tumor that is seen in the deep soft tissues of extremities, retroperitoneum and paratesticular region. It may be locally aggressive but has minimal to no metastatic potential. A subset of ALT/WDL progresses to DLPS which is capable of rapid growth and distant metastases.
• Myxoid/Round cell liposarcomas may be pure myxoid, myxoid and round cell, or pure round cell liposarcoma. Updated terminology for this tumor is here.
• Pleomorphic liposarcomas resemble undifferentiated pleomorphic sarcomas but contain pleomorphic lipoblasts. Most of the retroperitoneal pleomorphic liposarcomas are thought to be DLPS.