Exophytic adenocarcinoma of the stomach: CT findings

Exophytic adenocarcinomas of the stomach are tumors that have large extraluminal portions. Exophytic growth of gastric carcinoma is rare, and such tumor may be confused with gastric leiomyosarcoma. The purpose of this study was to assess the CT findings of exophytic adenocarcinoma of the stomach and to determine their value in distinguishing between it and gastric leiomyosarcoma.

Twenty patients with exophytic adenocarcinomas of the stomach confirmed by surgery or endoscopic biopsy were included in the study. CT scans were assessed retrospectively for the size, location, and character of the mass and the presence of adjacent thickening of the gastric wall and outlet obstruction.

The masses were from 5 to 14 cm in diameter (mean, 9 cm). The mass was in the gastric antrum in 11 cases, the body of the stomach in six cases, the body and antrum in two cases, and the gastric fundus and body in one case. CT showed an exogastric mass with a variable degree of internal low density or necrosis in all 20 cases. Thickening of the gastric wall adjacent to the mass appeared to be a specific finding of exogastric adenocarcinoma (n = 14); it was not seen in reported cases of leiomyosarcoma. Gastric outlet obstruction was seen in four cases, and ulcer was detected in eight cases. The degree of low density or necrosis within the mass was minimal in eight cases, moderate in seven cases, and severe in five cases.

Our results suggest that CT findings of thickening of the gastric wall adjacent to an exogastric mass, representing spread of cancer to adjacent gastric wall, and/or gastric outlet obstruction are typical of exophytic adenocarcinoma of the stomach and allow distinction between it and gastric leiomyosarcoma.