Table 1
Risk assessment categories of gastrointestinal stromal tumours based on size and mitotic index
Risk category
Size (cm)
Mitoses (HPF)
HPF, high power field.
Data from Fletcher
et al.
5
Very low risk
<2
⩽5/50
Low risk
2–5
⩽5/50
Intermediate risk
⩽5
5–10/50
5–10
⩽5/50
High risk
>5
>5/50
>10
Any mitotic rate
Any size
>10/50