Chromosome 8 Polysomy Accounting for MYC Over-Expression in Angiosarcoma Arising as Somatic-Type Malignancy in Metastatic Teratoma. Case Report.

MYC over-expression by immunohistochemistry (IHC) is utilised in routine pathology practice as a surrogate marker for amplification, which plays a key oncogenic role in post-irradiation and chronic lymphedema-associated angiosarcoma. We present the case of a 32-year old male, who presented with high-grade angiosarcoma arising in a background of metastatic testicular teratoma. IHC for MYC showed strong nuclear expression in the angiosarcoma cells prompting the consideration of post-irradiation-induced angiosarcoma but our patient did not undergo radiotherapy.

Lessons learnt from MDM2 fluorescence in-situ hybridisation analysis of 439 mature lipomatous lesions with an emphasis on atypical lipomatous tumour/well-differentiated liposarcoma lacking cytological atypia.

Aims: Amplification of the murine double minute-2 (MDM2) gene, which is usually detected with fluorescence in-situ hybridisation (FISH), is the key driving event for atypical lipomatous tumours (ALTs)/well-differentiated liposarcomas (WDLs). We sought to determine the concordance between the histopathological findings and MDM2 FISH in the diagnosis of ALT/WDL, and to identify the histological features of MDM2-amplified tumours lacking classic atypia.

Methods And Results: We performed a retrospective analysis of all mature lipomatous lesions subjected to MDM2 FISH analysis at our institution.