Most reported cases involve invasive ductal carcinoma, and IHC panels typically include markers such as SYN and CgA for pheochromocytoma, and ER, PR, HER2, GATA3, and mammaglobin A for breast carcinoma (3, 4, 6). The gene discussed is ERBB2; the disease is hereditary pheochromocytoma-paraganglioma.