Immunohistochemical examination of the tumor showed that chromogranin A and synaptophysin were positive (Fig. 2, B, C), leading to the final diagnosis of left pheochromocytoma; Succinate dehydrogenase subunit B (SDHB) was positive (Fig. 2D); cytochrome P450 (CYP) 11B2 was negative, Ki 67 was weakly positive (Fig. 2, E, F), and ACTH was negative (Fig. 3A). This evidence concerns the gene CHGA and pheochromocytoma.