Table 2.
Weiss criteria. 60
| Criteria | Score awarded a | |
|---|---|---|
| 0 | 1 | |
| Nuclear grade | I/II | III/IV |
| Mitosis | ⩽5 per 50 HPF | >5 per 50 HPF |
| Atypical mitoses | Absent | Present |
| Clear cell component | ⩽25% of tumor | >25% of tumor |
| Diffuse architecture | ⩽1/3 of tumor | >1/3 of tumor |
| Confluent necrosis | Absent | Present |
| Venous invasion | Absent | Present |
| Sinusoidal invasion | Absent | Present |
| Capsular invasion | Absent | Present |
a
A total score of >3 is suggestive of ACC.
N
uclear grading is based on the Fuhrman nuclear grading system used in renal cell carcinoma. 67
HPF, high power fields.