Table 1: Risk of aggressive behaviour in GISTs (adapted from Fletcher et al., 2002) [10].

SizeMitotic count
(mitoses per 50 high powered fields)

Very low risk<2 cm<5
Low risk2–5 cm<5
Intermediate risk<5 cm6–10
5–10 cm<5
High risk>5 cm>5
>10 cmAny mitotic rate
Any size>10