MKI67 and hereditary pheochromocytoma-paraganglioma: More recently, the COPPS score (Composite Pheochromocytoma/paraganglioma Prognostic Score), which is based on tumor size, the presence of necrosis and vascular invasion, and the loss of S100 and/or SDHB immunoreactivity but not including Ki67, has been proposed [131].