PHOX2B and paraganglioma: Both paraganglioma and panNETs with paraganglioma-like morphology show S100-positive sustentacular cells complicating the differential diagnosis, which is mainly based on the lack of low weight cytokeratins positivity and GATA3, tyrosine hydroxylase, PHOX2B, and Hand2 expression in the former [18, 72, 73].