Our hypothesis is that this co-occurrence of both rearrangements can reflect the morphologic differentiation of the tumour, with some areas of the tumours having a solid architecture, positive for the RET/PTC rearrangement, and other areas with follicular architecture, positive for PAX8/PPARγ, which would enable the identification of the rearrangements in the same tumour [44]. Here, RET is linked to neoplasm.