SDHB and adrenal gland pheochromocytoma: Therefore, a combination of the GAPP and SDHB immunohistochemistry (modified‐GAPP or M‐GAPP) has been suggested as a valuable tool for predicting metastatic disease.109 Koh et al validated the M‐GAPP score in a retrospective cohort of 72 PGL/PCC patients with a mean follow‐up of 44 months.