Is Duodenal Gastric Heterotopia Actually Oxyntic Metaplasia? An Age-Stratified Prevalence Study

The presence of oxyntic (body-type) glands in the duodenum is conventionally termed "gastric heterotopia" and is presumed to represent a congenital developmental anomaly. In contrast, gastric foveolar metaplasia of the duodenum is widely accepted as an acquired, reactive process. If duodenal gastric heterotopia were truly congenital, its prevalence should remain stable across age groups; if it is metaplastic in nature, prevalence should increase with age. A retrospective natural language search was performed for all cases diagnosed as "gastric heterotopia" in duodenal biopsies at a single academic medical center over a 10-year period (6/2013-4/2023). The prevalence of gastric heterotopia was calculated for each decade of life. Of 44,637 patients with duodenal biopsies, 846 (1.90%) had gastric heterotopia. The prevalence rose from 0.22% in patients aged 0-10 years to 4.05% in patients aged 91-100 years, representing an approximately 20-fold increase. The Spearman correlation between age group and prevalence was 0.988. The strong, monotonic relationship between patient age and prevalence of duodenal oxyntic glands is less consistent with a congenital process and instead supports a metaplastic etiology. The term "oxyntic metaplasia" is proposed as a more pathophysiologically accurate descriptor for this finding.