Primary MALT lymphomas of the stomach: a pathological study of 18 cases.

AIM It is doubtful that whoever is suffering from gastric malt lymphoma will escape from the disease, if treated with medication against helicobacter pylori. MATERIAL AND METHODS A cohort of 18 patients was analysed. Ten hosts had primary gastric malt lymphoma and were treated with gastric resection as the initial therapy. Eight hosts received antibiotics against Helicobacter pylori as the initial treatment. In all 18 patients Helicobacter pylori status, endoscopic findings and pathology features were evaluated. Immunohistochemistry was performed to assess the bcl-2 and p53 status. RESULTS Patients with low grade malt lymphoma: a) were Helicobacter pylori positive (5 of 5); b) had a superficial lesion (5 of 5); c) had no lymph node involvement (5 of 5); and d) were downstaged by comparison to patients with high grade tumor. Bcl-2 was positive in 4 of 5 low grade tumors, and p53 was positive in 12 of 13 high grade ones. Investigation of patients with 5-year follow up (n = 18) revealed that all but one low-grade tumors remained superficial with no progression. These tumors were bcl-2+/p53-, and the one with a bcl-2+/p53+ immunophenotype progressed to an ulcerated low-grade tumor after disappearance of Helicobacter pylori. Complete regression was found in 6 of 8 patients from the non surgically treated group (n = 8) after Helicobacter pylori eradication. These tumors were superficial/low grade/node negative/bcl-2+/p53 inconclusive (n = 2), superficial/low grade/node negative/bcl-2+/p53- (n = 2), and ulcerative/high grade/node negative/bcl-2+/p53- (n = 2). The two persistent tumors were ulcerative/high grade/node negative/bcl-2+/p53+. CONCLUSION Gastric malt lymphoma Helicobacter pylori+/superficial/low grade/bcl-2+/p53- will disappear after Helicobacter pylori eradication.