Table 1.
Parameters and score in grading of adrenal pheochromocytoma and paraganglioma (GAPP).
| Parameters | Score |
|---|---|
| Histological Pattern | |
| Zellballen | 0 |
| Large and irregular cell nest | 1 |
| Pseudorosette (even focal) | 1 |
| Cellularity | |
| Low (less than 150 cells/U *) | 0 |
| Moderate (150–250 cells/U *) | 1 |
| High (more than 250 cells/U *) | 2 |
| Comedo Necrosis | |
| Absence | 0 |
| Presence | 2 |
| Vascular or Capsular Invasion | |
| Absence | 0 |
| Presence | 1 |
| Ki67 Labelling Index | |
| Less than 1% | 0 |
| 1–3% | 1 |
| More than 3% | 2 |
| Catecholamine Type | |
| Adrenaline type (A **, or A + NA ***) | 0 |
| Noradrenaline type (NA, or NA + DA ****) | 1 |
| Non-functioning type | 0 |
| Total Maximum Score | 10 |
U *: Cells in Unit of 10 × 10 mm micrometer under high power field (×400); A **: Adrenaline; NE ***: Noradrenaline; DA ****: Dopamine.