Evolution of
gastrinoma tumoral mass, fasting serum
gastrin concentrations, and gastric endocrine cells has been analyzed in 21 patients with the
Zollinger-Ellison syndrome committed to long-term
omeprazole treatment (up to 7.75 years, median 37 months).
Gastrinoma growth was seen in eight patients. Significant increase in serum
gastrin was only observed in the group of patients with
gastrinoma growth. Fundic argyrophil cell densities were correlated with serum
gastrin (r' = 0.68, P = 0.002). Argyrophil and
antral gastrin cell densities significantly increased during the survey, but increases were greater in the group with
gastrinoma growth (respectively, +136% and +131%) than in the other group (respectively, +34% and +43%). Progression in the degree of argyrophil cell
hyperplasia, noted qualitatively, was observed in 11 patients. Fundic
carcinoids developed in three of these 11 patients, all three having
multiple endocrine neoplasia type 1 (MEN 1). Positive linear individual correlations (r > or = 0.85) between argyrophil cell densities and corresponding durations of
omeprazole treatment were found in nine of the 10 patients studied at least three times and who had a clear-cut increase in those cell densities. Thus, increase in serum
gastrin and fundic argyrophil cell densities appeared closely associated with
gastrinoma growth; however, duration of
drug-induced
hypochlorhydria may also affect cell proliferation.