Vanished MDM2 amplification in a poorly differentiated sarcoma with amplified TERT-TRIO fusion gene: a targeted effect of radiotherapy?

The identification of genetic alterations in sarcoma may give precious clues for the diagnosis. The detection of MDM2 amplification has an important impact since it may orientate towards a dedifferentiated liposarcoma (DDLPS) or more rarely towards an intimal sarcoma. Here we describe a poorly differentiated sarcoma initially diagnosed as a DDLPS, mainly on the basis of FISH analysis that detected MDM2 amplification. The patient was treated by adjuvant radiotherapy and, when the tumor recurred a few years later, MDM2 amplification was not observed anymore. We report the clinical, immunohistological, genomic and molecular description of the primary tumors and his recurrences. Genetic alterations in sarcoma