CAP16 Abstract Highlights - Astrocytoma With a Distinct Molecular Signature: MYB Rearrangement and EGFR Amplification

We report the first case of a pediatric astrocytoma with both MYB rearrangement and EGFR amplification. A 3-year-old boy was found to have a T2 hyperintense, nonenhancing mass in theleft temporal lobe after minor head trauma. Histology showed a diffuse astrocytic tumor with low cell density and bland cytology. Mitotic figures were present, albeit focally, prompting a diagnosis of anaplastic astrocytoma. No necrosis or microvascular proliferation was identified. The Ki-67 labeling index, while generally low, rose to approximately 20%, corresponding to regions of mitotic activity. Interphase fluorescence in situ hybridization analysis showed both rearrangement of MYB in two-thirds of cells and amplification of EGFR in approximately one-quarter of cells. This combination of low- and high-grade molecular features in a pediatric diffuse astrocytoma is so far unique and mayrepresent the molecular correlate of the rare clinical scenario where a pediatric diffuse astrocytoma, with MYB rearrangement, progresses to high-grade disease.
Source: neuropathology blog - Category: Radiology Tags: CAP16 abstracts molecular studies neoplasms Source Type: blogs