[87] Myxoid Liposarcoma with Heterologous Components: Dedifferentiation or Metaplasia? A FISH and CGH-Array Documented Case Report

Noelle Weingertner, Agnes Neuville, Frederic Chibon, Valere Litique, Laure Foessel, Antonio Di Marco, Luc Marcellin, Jean-Pierre Ghnassia. Hopitaux Universitaires de Strasbourg, Strasbourg, France; Insitut Bergonié, Bordeaux, France; Centre Paul Strauss, Strasbourg, France

Background: Heterologous differentiation in myxoid liposarcoma (MLS) is a rare phenomenon. Few cases were thus far reported, often without molecular assays, and the concept of “dedifferentiated” myxoid liposarcoma remains controversial.
Design: We describe a primary MLS with malignant chondroid and osseous components that affected the right thigh of a 27-year-old woman. We wondered if these areas represent dedifferentiated components or simply metaplasia, and performed FISH and CGH-array assays in the myxoid liposarcoma component and in the chondroid component.
Results: FISH analysis demonstrated a DDIT3 gene rearrangement in the two components, and CGH-array analysis did not detect any gain or loss of DNA regions, neither in the myxoid liposarcoma component, nor in the chondroid component. Thus, our results demonstrated that the two components have the same molecular alterations, and particularly, the heterologous component did not demonstrate additional ones.
Conclusions: Our FISH and CGH-array documented case suggest that the heterologous components seen in some myxoid liposarcomas reflects rather a metaplastic phenomenon than a true dedifferentiation phenomenon, challenging the concept of “dedifferentiated myxoid liposarcoma.”
Category: Bone & Soft Tissue

Monday, March 4, 2013 1:00 PM

Poster Session II # 30, Monday Afternoon

 

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