FGFR2 and adrenal gland pheochromocytoma: In conclusion, this study demonstrated the feasibility of FGFR2-FISH assay using biopsy specimens of BTC, and showed that 7.4% of cases in advanced/recurrent ICC retained FGFR2 rearrangements, and 3.6% cases in advanced/recurrent PCC also carried the alterations.