Wei SC, Xu L, Li WH, et al. - Researchers investigated the relationship among risk stratification and the shape of GISTs. A total of 101 individuals with primary GISTs were verified by pathology and immunohistochemistry and these people undergone enhanced CT examination. Pathologic sizes of all lesions were 1 to 10 cm. The four angles of the quadrangle ABCD were measured and each angle named by its summit (A, B, C, D). For regular lesions, they took angles A and B as a big angle (BiA) and small-angle (SmA) and for irregular lesions, they contrasted A/B ratio and D/C ratio and chose the greater ratio for study. The BiA/SmA ratio was an autonomous predictor for the risk level of GISTs. It was found that quantifying tumor shape has better predictive effectiveness in comparison with longest diameter in prognosticating the risk level and mitotic value of GISTs, particularly for high-risk grading and mitotic value > 5/50HPF.