Molecular fingerprinting reflects different histotypes and brain region in low grade gliomas

Samantha Mascelli, Annalisa Barla, Alessandro Raso, Sofia Mosci, Paolo Nozza, Roberto Biassoni, Giovanni Morana, Martin Huber, Cristian Mircean, Daniel Fasulo, Karin Noy, Gayle Wittemberg, Sara Pignatelli, Gianluca Piatelli, Armando Cama, Maria Luisa Garré, Valeria Capra, Alessandro Verri

Paediatric low-grade gliomas (LGGs) encompass a heterogeneous set of tumours of different histologies, site of lesion, age and gender distribution, growth potential, morphological features, tendency to progression and clinical course. Among LGGs, Pilocytic astrocytomas (PAs) are the most common central nervous system (CNS) tumours in children. They are typically well-circumscribed, classified as grade I by the World Health Organization (WHO), but recurrence or progressive disease occurs in about 10-20% of cases. Despite radiological and neuropathological features deemed as classic are acknowledged, PA may present a bewildering variety of microscopic features. Indeed, tumours containing both neoplastic ganglion and astrocytic cells occur at a lower frequency.