We report here about two novel tumours classified as extraventricular neurocytomas (EVN) using DNA-methylation profiling, associated with NTRK2 fusions instead of the usual FGFR1 alterations so far at Show more
We report here about two novel tumours classified as extraventricular neurocytomas (EVN) using DNA-methylation profiling, associated with NTRK2 fusions instead of the usual FGFR1 alterations so far attributed to this tumoural entity. We present the second detailed case of an intraventricular presentation in the MC EVN. Our findings broaden the spectrum of MC EVN and have implications in terms of diagnosis, therapy and terminology. Show less
Diffuse midline gliomas (DMG) H3 K27-altered are incurable grade 4 gliomas and represent a major challenge in neuro-oncology. This tumour type is now classified in four subtypes by the 2021 edition of Show more
Diffuse midline gliomas (DMG) H3 K27-altered are incurable grade 4 gliomas and represent a major challenge in neuro-oncology. This tumour type is now classified in four subtypes by the 2021 edition of the WHO Classification of the Central Nervous System (CNS) tumours. However, the H3.3-K27M subgroup still appears clinically and molecularly heterogeneous. Recent publications reported that rare patients presenting a co-occurrence of H3.3K27M with BRAF or FGFR1 alterations tended to have a better prognosis. To better study the role of these co-driver alterations, we assembled a large paediatric and adult cohort of 29 tumours H3K27-altered with co-occurring activating mutation in BRAF or FGFR1 as well as 31 previous cases from the literature. We performed a comprehensive histological, radiological, genomic, transcriptomic and DNA methylation analysis. Interestingly, unsupervised t-distributed Stochastic Neighbour Embedding (tSNE) analysis of DNA methylation profiles regrouped BRAF Show less