Table 3.

Grading of adrenal pheochromocytoma and paraganglioma (GAPP). Abbreviations: E, epinephrine; NE, norepinephrine; DA, dopamine; U, number of tumor cells in a square of a 10 mm micrometer observed under high-power magnification (×400).

Parameters	Score
Histological pattern Zellballen Large and irregular cell nest Pseudorosette	0 1 1
Cellularity Low (<150 cells/U) Moderate (150–250 cells/U) High (>250 cells/U)	0 1 2
Comedo necrosis Absence Presence	0 2
Vascular or capsular invasion Absence Presence	0 1
Ki67-labelling index (%) <1 1–3 >3	0 1 2
Catecholamine type E or E + NE NE or NE + DA Non-functioning	0 1 0
Total maximum	10