Fig. 1

ATXN1-NUTM1 gene fusion, confirmed by RT-PCR and Sanger sequencing (a). MRI identified a frontal mass. Enhancement after contrast injection (T1) (b). Representative histopathology. On the left, loose area with neuron-like tumor cells (*detail). On the right, increase in cell density (c). Fascicular architecture with three mitoses (arrows) (d). Chondroid-like, myxoid and hyalinized areas were observed (e). Undifferentiated cells with large nucleoli in a chondromyxoid background (f). Strong GFAP staining was observed. Tumor showed vascular proliferation (g). Neurofilament staining circumscribed the tumor mass with no significant staining within the tumor (h). p53 accumulated in tumor nuclei (i). Anti-NUT antibody staining showing homogeneous intranuclear expression (j)