Pseudolymphoma of the stomach. A clinicopathologic study of 15 cases.

Fifteen cases of gastric pseudolymphoma (GPL) were studied and classified into three subtypes: The nodular type, which is elevated, representing a submucosal tumor. Histologically, the tumor is composed of lymphoid hyperplasia with no associated ulcer. The lesion is well demarcated with no sinusoidal structure. Those findings indicate a nonreactive state. The ulcerative type, which usually is accompanied by deep ulceration with extensive fibrosis. The erosive type, which is infiltrated by extensive lymphoid hyperplasia in the propria mucosa and submucosa. The latter two types represent the reactive state in response to chronic gastric ulcer or inflammation. One of four ulcerative GPLs, however, was associated with focal malignant lymphoma which accounted for one of the fifteen GPL studied. Although there is a low incidence of malignant lymphoma among GPL patients, pseudolymphoma should be considered as a precursor lesion with malignant potential.