Gastric B-cell mucosa associated lymphoid tissue lymphoma: a clinicopathological study in 56 patients.

Clinico-pathological features of 56 patients with primary gastric lymphoma were evaluated retrospectively. All cases were regraded according to a classification of Isaacson et al into high grade and low grade B-cell mucosa associated lymphoid tissue lymphoma. A third group of mixed grade was recognised in 11 patients with low grade who also had occasional areas of high grade. Low grade and mixed grade patients had a 100% actuarial survival at 156 months, which was significantly better (p < 0.01) than that of 52% for patients with high grade disease. Different treatment methods--surgery, chemotherapy, or a combination of both--did not significantly affect survival. Low grade tumours occurred mainly in men with a history of several years, and who presented with non-specific gastric symptoms without remarkable exploratory or laboratory findings: most patients were in stage IE-IIE and achieved remission and cure. High grade can have a shorter history, systemic symptoms, abnormal exploratory and laboratory findings, gastric tumour masses, stage IV disease, and a worse outcome. The only significant prognostic factors for survival were the type of lymphoma and stage IV disease. These findings support the Isaacson classification system which separates two extreme groups of gastric lymphomas with different morphology, behaviour, and outcome. The presence of limited areas of high grade in a specimen showing low grade does not change the outcome but suggests that primary gastric lymphoma forms a continuum between these extreme types.