[Comparison of CT findings between gastric cancer and gastric lymphoma].

BACKGROUND & OBJECTIVE: It is difficult to discriminate progressive gastric cancer and gastric lymphoma by CT imaging, because incrassate gastric wall, lump in gastric cavity, confined gastric cavity, intumescent lymph node, and distant metastasis can be displayed in both of them. This study was to compare the CT findings between gastric cancer and gastric lymphoma to improve diagnosis of gastric tumors, especially for gastric lymphoma.

METHODS: CT images of 27 patients with pathologically proved progressive gastric cancer and 25 patients with pathologically proved gastric lymphoma were reviewed. Tumor location, appearance, scope of involvement, gastric wall thickness, mucous membrane, mucosal fold, serosa membrane, necrosis, enhancement degree and uniformity, involvement of other organs, and abdominal lymph nodes were observed.

RESULTS: White line sign was observed in 23 cases (85.2%) of gastric cancer, but not in the 25 cases of gastric lymphoma. The extent of white line sign in gastric cancers was larger in portal vein phase than in arterial phase. Enhancement degree outside the white line was higher in portal vein phase than in arterial phase in 13 cases (48.1%) of gastric cancer. The extent of involved gastric wall was smaller than 50% of the whole gastric wall in all the 27 cases of gastric cancer, while it was larger than 75% in 23 cases (85.2%) of gastric lymphoma. Gastric mucous membrane ulcer was found in all of the 27 cases (100%) of gastric cancer, while it was found in only 1 case (4.0%) of gastric lymphoma. Intumescent lymph nodes in two or more areas were found in 11 cases (40.0%) of gastric lymphoma, but not in gastric cancer. Intumescent lymph nodes in the retroperitoneal space below renal hilum were found in 8 cases (32%) of gastric lymphoma, but not in gastric cancer.

CONCLUSION: There are some different CT features between gastric cancer and gastric lymphoma, such as white line sign, gastric mucous membrane ulcer, extent of involved gastric wall, location of intumescent lymph nodes surrounding the stomach and in retroperitoneal space below renal hilum, and so on, which could be helpful in differential diagnosis of these two diseases.