Gastric gastrointestinal stromal tumours (2-5 cm): Correlation of CT features with malignancy and differential diagnosis

Purpose: The purpose of this study was to investigate the computed tomography (CT) features of 2 - 5 cm gastric gastrointestinal stromal tumors (GISTs), schwannomas and leimyomas which have close relationship with malignancy evaluation and differential diagnosis. Method: Seventy-six patients with pathologically confirmed gastric submucosal tumors (SMTs) between 2 - 5 cm were included in this study, including 60 GISTs, 10 schwannomas and 6 leiomyomas. CT imaging features were reviewed and quantitative parameters including CT values during nonenhanced phase (CTV-N), portal phase (CTV-P) and delayed phase (CTV-D) were recorded. The association of CT features with mitotic counts of GISTs and the significantly different CT features between GISTs and benign SMTs were analyzed. Results: The lobulated contour was significantly more common in GISTs with high mitoses (P < 0.05). The value of CTV-D/CTV-P was significantly lower in GISTs with high mitoses (P < 0.05) and it was an independent predictor for high-mitosis GISTs (P = 0.049, odds ratio [OR] = 186.445) with an area under the curve (AUC) of 0.722. CT features including heterogeneous enhancement and presence of necrosis or cystic degeneration were significantly suggestive of GISTs instead of benign SMTs (P < 0.05). The value of CTV-D/CTV-P was significantly higher in schwannomas than that in GISTs (P < 0.05) with an AUC of 0.853. The value of CTV-P/ CTV-N was significantly lower in leiomyomas than that in GISTs (P < 0.05) with an AUC of 0.883. Conclusions: Some qualitative and quantitative parameters on contrast-enhanced CT can be helpful in preoperative diagnosis and risk stratification of 2 - 5 cm gastric GISTs.