A lymphoproliferative abnormality of the intestine characterized by numerous visible mucosal nodules measuring up to, and rarely exceeding, 0.5 cm in diameter Histologically, hyperplastic lymphoid follicles with large germinal centers are seen in the lamina propria and superficial submucosa. There is enlargement of the mucosal B cell follicles caused by hyperplasia of the follicle centers; surrounded by a normal appearing mantle zone. Disease may involve the stomach, the entire small intestine, and the large intestine. [from
HPO]