GASTRIC ENDOCRINE CELL EVOLUTION IN PATIENTS WITH ZOLLINGER-ELLISON SYNDROME - INFLUENCE OF GASTRINOMA GROWTH AND LONG-TERM OMEPRAZOLE TREATMENT

Evolution of gastrinoma tumoral mass, fasting serum gastrin concentrat ions, and gastric endocrine cells has been analyzed in 21 patients wit h the Zollinger-Ellison syndrome committed to long-term omeprazole tre atment (up to 7.75 years, median 37 months). Gastrinoma growth was see n in eight patients. Significant increase in serum gastrin was only ob served in the group of patients with gastrinoma growth. Fundic argyrop hil cell densities were correlated with serum gastrin (r' = 0. 68, P = 0. 002). Argyrophil and antral gastrin cell densities significantly i ncreased during the survey, but increases were greater in the group wi th gastrinoma growth (respectively, + 136% and + 131%) than in the oth er group (respectively, +34% and +43%). Progression in the degree of a rgyrophil cell hyperplasia, noted qualitatively, was observed in 11 pa tients. Fundic carcinoids developed in three of these 11 patients, all three having multiple endocrine neoplasia type 1 (MEN 1). Positive li near individual correlations (r greater-than-or-equal-to 0.85) between argyrophil cell densities and corresponding durations of omeprazole t reatment 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 appeare d closely associated with gastrinoma growth; however, duration of drug -induced hypochlorhydria may also affect cell proliferation.