Primary gastric lymphoma versus gastric carcinoma: endoscopic US evaluation.

Endoscopic ultrasonography (US) enables high-resolution imaging of the stomach and can demonstrate the different layers of the gastric wall. It has therefore been proposed for use in evaluating the extension of gastric neoplasms. It was performed in nine patients with primary gastric non-Hodgkin lymphoma and in 36 with gastric carcinoma. The US and pathologic findings were correlated in three surgical specimens of gastric lymphoma. Three different US patterns were found in gastric lymphomas: a polypoid pattern (two cases), localized (two cases) or extended (five cases) hypoechoic infiltration, and thickening with superficial ulcerations. Infiltration was confined to the second and third layers of the gastric wall in six cases and was transmural in three. The study of the gastric lymphoma specimens confirmed the accuracy of US in demonstrating the extent of infiltration. Gastric carcinomas had a more echogenic pattern and a different trend of diffusion, with no extended longitudinal hypoechoic infiltration of the superficial layers or extended hypoechoic transmural infiltration.