Gastrointestinal Stromal Tumors: A Review of Case Reports, Diagnosis, Treatment, and Future Directions
Table 2
AFIP-Miettinen risk stratification system.
Risk stratification of primary GIST by mitotic index, size, and site*
Tumor parameters
Risk of progressive disease* (%)
Mitotic index
Size
Gastric
Duodenum
Jejunum/ileum
Rectum
≤5 per 50 hpf
≤2 cm**
None (0%)
None (0%)
None (0%)
None (0%)
>2 ≤ 5 cm
Very low (1.9%)
Low (4.3%)
Low (8.3%)
Low (8.5%)
>5 ≤ 10 cm
Low (3.6%)
Moderate (24%)
(Insuff. data)
(Insuff. data)
>10 cm
Moderate (10%)
High (52%)
High (34%)
High (57%)
≤2 cm
None†
High†
(Insuff. data)
High (54%)
>5 per 50 hpf
>2 cm ≤ 5 cm
Moderate (16%)
High (73%)
High (50%)
High (52%)
>5 cm ≤ 10 cm
High (55%)
High (85%)
(Insuff. data)
(Insuff. data)
>10 cm
High (86%)
High (90%)
High (86%)
High (71%)
These Data are based on long-term followup of 1055 gastric, 629 small intestinal, 144 duodenal, and 111 rectal GISTs. Abbreviations: GIST—gastrointestinal stromal tumor; hpf—high power field. Insuff—insufficient.
*Defined as metastasis or tumor-related death. †Denotes small numbers of cases. Adapted from Miettinen and Lasota, 2006 with permission from Elsevier [48].
