Dysplastic changes in gastric fundic gland polyps of patients with familial adenomatous polyposis

Fundic gland polyps are the most common gastric lesion in patients with familial adenomatous polyposis and are traditionally considered a condition with no malignancy potential. However, some reports have recently questioned this view.

To prospectively evaluate their prevalence and the associated dysplastic/malignant changes in a series of affected patients.

Thirty-seven affected patients were carefully investigated by upper endoscopy over a three-year period. Multiple (at least 10) complete excisions of any representative polyp of the body-fundus were performed and a thorough pathological search for microscopic adenomatous/dysplastic changes carried out.

Of 37 patients, 19 (51.3%) showed gastric fundic gland polyposis and 18 of them gave consent for polypectomies. Overall, 425 endoscopic polypectomies were performed, with a mean of 23.6 +/- 14.6 per patient. At pathology, all excised polyps of the body-fundus were found to be fundic glandular. Microscopic adenomatous changes within such polyps were identified in 8 (44.4%) patients. All the adenomatous foci revealed mild dysplasia with no case of severe atypia or carcinoma. Patients with microadenomas showed a significantly higher total number of gastric polyps compared with those without microadenomas (p < 0.03). No other differences between the two groups were observed. Two further patients presented microadenomas in apparently normal antral mucosa and one also showed a 6 mm antral adenoma with mild dysplasia. Finally, the search for Helicobacter pylori was always negative.

Patients with familial adenomatous polyposis and gastric fundic gland polyps have a high prevalence of microscopic adenomatous foci within such lesions; nevertheless, these foci seem not to be associated with signs of severe atypia or carcinoma. Moreover, microadenomas are ubiquitous throughout the stomach, as well as in the rest of the gut, and their natural history is still undefined. Thus, their malignancy potential remains uncertain. More extensive follow-up is warranted to better investigate the long-term biological behaviour of these lesions but, at present, our data do not support the need for a change in the usual intervals of upper endoscopy surveillance in familial polyposis patients with or without gastric fundic glands polyps.