Dedifferentiated Liposarcoma : Introduction

Comments:
Introduction: Dedifferentiated liposarcoma (DLPS) is a non-lipomatous, undifferentiated sarcoma of variable grade that arises within an atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL). It makes up about 18% of all liposarcomas. Dedifferentiation usually occurs in the primary tumor or it may develop subsequently in a recurrence or metastasis. Dedifferentiation mainly occurs in the deep-seated tumors (retroperitoneum, mediastinum, paratesticular) and is rare in subcutaneous lesions.

The tumor usually has a biphasic appearance (as shown here) consisting of a clearly recognizable ALT/WDL (right half) and a sharply demarcated dedifferentiated area (left half). Besides ALT/WDL, dedifferentiation with emergence of a higher grade neoplasm is known to occur in well-differentiated chondrosarcomas, chordomas, and parosteal osteosarcomas.