Table 1.

Pheochromocytoma and paraganglioma risk stratification systems

Parameter	Score
Pheochromocytoma of the adrenal gland scaled score (PASS)
Large nests or diffuse growth (> 10% of tumor volume)s	2
Central or confluent tumor necrosis	2
High cellularity	2
Cellular monotony	2
Tumor cell spindling	2
Mitotic figures > 3/10 high-power field	2
Atypical mitotic figure(s)	2
Extension into adipose tissue	2
Vascular invasion	1
Capsular invasion	1
Marked nuclear pleomorphism	1
Nuclear hyperchromasia	1
Total	20*
*A score > 4 implies a higher risk of metastases

Grading of adrenal pheochromocytoma and paraganglioma (GAPP)
Architectural pattern
Regular cell nest	0
Large and irregular cell nest	1
Pseudorosette	1
Cellularity
Low (< 150 cells/U)	0
Moderate (150–250 cells/U)	1
High (> 250 cells/U)	2
Presence of comedo-type necrosis	2
Presence of vascular or capsular invasion	1
Ki67 labeling index (%)
< 1	0
1–3	1
> 3	2
Catecholamine type
Adrenergic type (± noradrenaline)	0
Noradrenergic type (noradrenaline ± dopamine	1
Nonfunctioning	0
Total maximum score	10

Grade	Score	Metastatic rate (%)	5-year survival (%)
Well differentiated	0–2	3.6	100
Moderately differentiated	3–6	60	66.8
Poorly differentiated	7–10	88.2	22.4

Composite pheochromocytoma/paraganglioma prognostic score (COPP)
Focal or confluent tumor necrosis	5
Loss of S100 expression	2
Vascular invasion	1
Loss of SDHB expression	1
Size > 7 cm	1
A score greater than or equal to 3 means a high metastatic risk