For spindle cell oncocytomas and pituicytomas, individual mutations affecting the MAPK signaling pathway (SND1, FAT1, HRAS), as well as in other oncogenes (i.e. MEN1, TSC1, CBL, FZD7, PIK3GC, SBK1, CDKN2A/B, SKT11, SMARCA4, CIC, SMARCB1, NF1, NF2) have been reported in case reports or limited case series (11, 21, 22). This evidence concerns the gene FAT1 and pituicytoma.