Table 3

Risk stratification of gynecologic PEComas1 42 43 219

General criteriaModified gynecologic+specific criteria
Benign<5 cm, non-infiltrative
Non-high nuclear grade
Mitotic count of ≤1 mitosis/12 mm²
No necrosis
No vascular invasion
Uncertain malignant potentialNuclear pleomorphism/multinucleated giant cells or <5 cmLess than three of the following features:
  • ≥5 cm

  • High nuclear grade

  • Mitotic count of >1 mitosis/12 mm²

  • Necrosis

  • Vascular invasion

MalignantTwo or more of the following features:
  • >5 cm

  • Infiltrative

  • High nuclear grade

  • Mitotic count of >1 mitosis/12 mm²

  • Necrosis

  • Vascular invasion

Three or more features
  • Mitotic count: 1 mitosis in 50 high-power fields of diameter 0.55 mm, area 0.24 mm².