Fundic gland polyps: a still elusive entity on the eve of the year 2000.

Fundic gland polyps (FGPs) are tiny multiple sessile polyps of the acid-secreting gastric mucosa. They have been described both in a sporadic form, mainly in middle-aged females, and in a syndromic form, associated with familial adenomatous polyposis (FAP)-Gardner's syndrome and attenuated variants (AFAP). They share the same histology, characterised by superficial and deep cystic dilatations, shortened gastric pits, with an inconspicuous lamina propria. They have been for a long time described as innocuous lesions, but some recent reports have shown that FGPs may harbour dysplastic foci and ultimately (particularly syndromic polyps) gastric cancer. Factors influencing their genesis are unknown. A circulating factor in FAP patients has been postulated and a role of female hormones has been suggested for sporadic FGPs. Whereas patients with sporadic FGPs have normal basal acid output, normal fast serum levels of gastrin and pepsinogen I, the role of gastrin seems crucial for the development of cystic changes in flat body-fundus mucosa, and for the appearance of FGPs in patients with Zollinger-Ellison syndrome. A role of H. pylori induced gastritis has been excluded. Actually, patients with both sporadic and syndromic FGPs appear consistently free from H. pylori colonisation, again for an unknown factor(s). Some recent reports have claimed a role for omeprazole in the genesis of FGPs, a highly controversial issue. Ultimately, the nature of FGPs is still debated: some have interpreted them as hamartomatous lesions, others as a peculiar form of hyperplastic polyp.