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. 2021 Apr 6;36(2):322–338. doi: 10.3803/EnM.2020.908

Table 5.

Comparison of Two Systems Predicting Pheochromocytoma and Paraganglioma Metastatic Potential

Parameter PASS (score if present)
Only PHEO		 GAPP (points scored)
Both PHEO and PGL
Criteria (no. of subject)

  1. Large nests or diffuse growth (2)

  2. Central or confluent tumor necrosis (2)

  3. High cellularity (2)

  4. Cellular monotony (2)

  5. Tumor cell spindling (2)

  6. Mitotic figures >3/10 HPF (2)

  7. Atypical mitotic figure(s) (2)

  8. Extension into adipose tissue (2)

  9. Vascular invasion (1)

  10. Capsular invasion (1)

  11. Profound nuclear pleomorphism (1)

  12. Nuclear hyperchromasia (1)

  1. Histological pattern

    • - Zellballen (0)

    • - Large and irregular cell nest (1)

    • - Pseudorosette (even focal) (1)

  2. Cellularity

    • - Low (<150 cells/U) (0)

    • - Moderate (150–250 cells/U) (1)

    • - High (more than 250 cells/U) (2)

  3. Comedo necrosis

    • - Abscence (0)/Presence (2)

  4. Vascular or capsular invasion

    • - Abscence (0)/Presence (1)

  5. Ki67 labelling index (%)

    • - <1 (0)/1–3 (1)/>3 (2)

  6. Catecholamine type

    • - Epinephrine type (0)

    • - Norepinephrine type (1)

    • - Non-functioning type (0)
Total score 0–20 0–10
Risk groups 0–3: benign fashion
4–20: biologically aggressive behavior		 0–2: Well-differentiated type
3–6: Moderately differentiated type
7–10: Poorly differentiated type
Sensitivitya 100% 90%
Specificitya 75% 87%

PASS, Pheochromocytoma of the Adrenal Gland Scaled Score; PHEO, pheochromocytoma; GAPP, Grading of Adrenal Pheochromocytoma and Paraganglioma; PGL, paraganglioma; HPF, high-power field.

a

For detection of malignancy.