Computed tomography imaging characteristics of synchronous gastrointestinal stromal tumors in patients with gastric cancer and correlation with clinicopathological findings.

This study was conducted to analyze the computed tomography (CT) imaging and clinicopathological characteristics of synchronous gastrointestinal stromal tumors (GISTs) in patients with gastric cancer. We retrospectively reviewed the CT images in 18 cases of immunohistochemically confirmed synchronous GISTs in patients with primary gastric cancer. Relevant histology and clinical data were also obtained. Multi-slice CT (MSCT) identified suspected synchronous GISTs in 26 patients, of which 18 were finally confirmed. Of the 18 patients, 12 were male and 6 female, with a mean age of 69.2 years. All 18 lesions were discovered as a solitary mass, ranging in size from 1.0 to 6.5 cm (mean, 2.2 cm). The lesions were predominantly located in the gastric fundus and were characterized by an ovoid shape, well-defined margins and isodensity, with slight to moderate gradual enhancement on MSCT. There was no evidence of necrosis, hemorrhage or cystic degeneration, irrespective of the tumor size. Synchronous GISTs exhibited spindle cell morphological characteristics and specific immunohistochemical properties, and were classified as being of low or very low malignant potential. In conclusion, since gastric cancer patients with a synchronous GIST are rare, a solitary, ovoid and well-defined mass with slight to moderate gradual enhancement following contrast agent injection may be suggestive of this diagnosis, although detection of synchronous GISTs does not appear to significantly affect therapy and outcome.