Table 1 Classification of PEComas proposed by Folpe et al
From: A rare case of perivascular epithelioid cell tumor (PEComa) of the greater omentum
Benign | Uncertain malignant potential | Malignant | |
|---|---|---|---|
Criteria | No worrisome features | Nuclear pleomorphism/multinucleated giant cells only | Two or more worrisome features |
Size < 5 cm | or | Size > 5 cm | |
Non-infiltrative | Size > 5 cm only | Infiltrative | |
Non-high nuclear grade and cellularity | High nuclear grade and cellularity | ||
Mitotic rate ≦ 1/50HPF | Mitotic rate ≧ 1/50HPF | ||
No necrosis | Necrosis | ||
No vascular invasion | Vascular invasion |