MDM2 amplification and fusion gene ss18-ssx in a poorly differentiated synovial sarcoma: A rare but puzzling conjunction.

The detection of specific alterations by genetic analyses has been included in the diagnostic criterions of the World Health Organization's classification of soft tissues tumors since 2013. The presence of a SS18 rearrangement is pathognomonic of synovial sarcoma (SS). MDM2 amplification is strongly correlated to well-differentiated or dedifferentiated liposarcoma (DDLPS) in the context of sarcoma.

Prognostic value of HMGA2, CDK4, and JUN amplification in well-differentiated and dedifferentiated liposarcomas.

HMGA2, CDK4, and JUN genes have been described as frequently coamplified with MDM2 in atypical lipomatous tumor, well-differentiated liposarcoma, and dedifferentiated liposarcoma. We studied the frequency of amplification of these genes in a series of 48 dedifferentiated liposarcomas and 68 atypical lipomatous tumors/well-differentiated liposarcomas. We correlated their amplification status with clinicopathological features and outcomes.

Microfoci of malignant progression in diffuse low-grade gliomas: towards the creation of an intermediate grade in glioma classification?

Low-grade gliomas (GII) inescapably progress to high-grade gliomas (GIII). The duration of this transition is highly variable between patients and reliable predictive markers do not exist. We noticed in a subset of cases of GII, obtained by awake neurosurgery, the presence of microfoci with high cellular density, high vascular density, or minimal endothelial proliferation, which we called GII+.

Identification of PPAP2B as a novel recurrent translocation partner gene of HMGA2 in lipomas.

Most lipomas are characterized by translocations involving the HMGA2 gene in 12q14.3. These rearrangements lead to the fusion of HMGA2 with an ectopic sequence from the translocation chromosome partner.