Comprehensive genetic analysis of a paediatric pleomorphic myxoid liposarcoma reveals near‐haploidization and loss of the RB1 gene

Abstract

The results support the notion that PML is a distinct type of liposarcoma, associated with a spectrum of somatic mutations that is different from that in other liposarcoma subtypes. The findings in the present case, combined with previous data, suggest that PML develops through combinations of numerical chromosome aberrations, possibly initialized by haploidization. The results also suggest that inactivation of RB1 is pathogenetically important.

Genomic and transcriptomic features of dermatofibrosarcoma protuberans: Unusual chromosomal origin of the COL1A1-PDGFB fusion gene and synergistic effects of amplified regions in tumor development

“…From eight of the samples analyzed by SNP array, also targeted DNA sequencing of 50 neoplasia-associated genes was performed ( Table 1 ), using the Ion AmpliSeq Cancer Hot Spot Panel v2 (ThermoFisher Scientific, Waltham, MA, USA) as described [35] . Ten samples were analyzed by RNA-seq ( Table 1 ), as described [36] .…”

Recurrent Pleomorphic Myxoid Liposarcoma in a Patient With Li-Fraumeni Syndrome

“…In addition, MDM2 amplifications that are associated with atypical lipomatous tumor and dedifferentiated liposarcoma have not been detected in PML. 1,3,4 Pleomorphic liposarcomas display complex genetic findings with aneusomy and structural rearrangements, which are different from chromosomal alterations that have been reported in 2 cases of PML with genetic analysis. 3,4 Available data from the few studies with genomic analysis support the classification of PML as a distinct subtype of liposarcoma.…”

“…1,3,4 Pleomorphic liposarcomas display complex genetic findings with aneusomy and structural rearrangements, which are different from chromosomal alterations that have been reported in 2 cases of PML with genetic analysis. 3,4 Available data from the few studies with genomic analysis support the classification of PML as a distinct subtype of liposarcoma. 3,4 Due to rarity of PML, these tumors have not been well studied and it is not known whether PML has a characteristic cytogenetic or molecular genetic abnormality.…”

“…5 A few additional cases of PML with similar histologic findings have also been described in literature. 3,4,6 Pleomorphic myxoid liposarcoma contains a variable combination of histological features of conventional myxoid liposarcoma and pleomorphic liposarcoma. 1,2 Despite the resemblance to conventional myxoid liposarcoma, PML is a very aggressive tumor with frequent local recurrences, distant metastasis, and poor prognosis.…”

“…1,2 The limited genetic data available for this subtype indicate that it lacks the characteristic genetic aberrations associated with other types of liposarcomas and supports its classification as a distinct type of liposarcoma. 1,3,4 We present a rare case of a PML presenting as a second primary neoplasm in a 34-year-old man who was diagnosed with TP53 gene mutation and Li-Fraumeni syndrome (LFS) in subsequent genetic testing.…”