| England DM, et al 1989 | De Perrot M, et al 2002 | Tapias LC, et al 2013 | Diebold M, et al 2017 |
Histologic risk factors for malignancy |
Mitotic figures per 10 HPF | >4 | >4 | ≥4 | ≥4 |
Hypercellularity | + | + | + | |
Pleomorphism | + | + | | |
Necrosis | + | + | + | + |
Hemorrhage | + | | + | |
Stromal/vascular invasion | | + | | |
Anatomic high risk factors |
Size | >10 cm | | ≥10 cm | ≥10 cm |
Pedunculation | Sessile | Sessile | Sessile | |
Site | Parietal pleura | Not included | Parietal pleura | |
Biomarker risk factors |
MIB-1 proliferation index | | | | ≥10% |
Number of criteria needed for high risk ("malignant") diagnosis |
| 1 or more histologic criteria | 1 or more histologic criteria | Any 3 histologic and anatomic risk factors | 2 or more histologic, anatomic, or biomarker risk factors |