The sign of origination stomach wall hyper-enhancement facilitates the diagnosis of exogenic gastrointestinal stromal tumor

Objective To explore the significance of the origination stomach wall hyper-enhancement sign and the polar distribution of necrosis and cyst component in differential diagnosis of exogenic gastrointestinal stromal tumor (GIST). Methods CT images of pathologically proven typeⅢ GIST (n=18) and other tumors from adjacent organ (pancreatic neuroendocrine tumor, n=6; SPT, n=8; HCC, n=2) with fat space disappeared between stomach wall and the tumors were analyzed prospectively. The status of the origination stomach wall hyper-enhancement sign and the polar distribution of necrosis and cyst component were recorded. The longest diameters and CT values (HU) on arterial and venous phases were measured. Results The ratio of origination stomach wall hyper-enhancement sign in GIST (9/15) was higher than other organ originated tumors (0/16) (χ2=12.857, P=0.007). On the polar distribution of necrosis and cyst component, the necrosis and cyst component of GIST was more prone to deviate away from gastric wall than the other organ originated tumors, but without statistical significance (χ2=5.947, P=0.051). There was no significance demonstrated in longest diameters (Z=-0.587, P=0.570) and CT values of both arterial (Z=-0.829, P=0.412) and venous phases (Z=-1.450, P=0.147). Conclusion The origination stomach wall hyper-enhancement sign can facilitate CT in differential diagnosis of gastric exogenic gastrointestinal stromal tumor. Key words: GIST; Tomography, X-ray computed; Diagnosis