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Case Reports
. 2026 Jan 22;18(1):e102050.
doi: 10.7759/cureus.102050. eCollection 2026 Jan.

Spurious Elevations of Chromogranin A in the Setting of Autoimmune Metaplastic Atrophic Gastritis

Elizabeth Jose  1 , Ariana Ambrosio  2 , Jesse F Simon  3 , Jeffrey H Schneider  4
Affiliations
Case Reports

Spurious Elevations of Chromogranin A in the Setting of Autoimmune Metaplastic Atrophic Gastritis

Elizabeth Jose et al. Cureus. .

Abstract

Autoimmune metaplastic gastritis (AMAG) is a form of autoimmune gastritis that is characterized by the immune system's attack on gastric parietal cells, leading to chronic inflammation. Gastric neuroendocrine tumors (GNETs) are rare neoplasms that can develop in the gastrointestinal tract in the presence of AMAG. This case presents a 69-year-old female who presented with dyspepsia, and on subsequent endoscopic evaluation, she was found to have AMAG in the context of elevated levels of serum chromogranin A (CgA) and gastrin, suggestive of a GNET. Despite an extensive diagnostic workup, including imaging, colonoscopy, small bowel follow-through, capsule study, and oncology workup, no GNET was identified. She was also found to have antibodies to parietal cells, suggestive of pernicious anemia. The elevated markers were attributed to enterochromaffin cell hyperplasia, secondary to hypergastrinemia from AMAG. This case invites a discussion about the need for more evidence-based guidelines in the workup and monitoring of spurious elevations of CgA and gastrin in the presence of AMAG. It also highlights the importance of careful and intentional clinical evaluation to avoid unnecessary tests and costs to the patient.

Keywords: autoimmune metaplastic gastritis; chromogranin a; enterochromaffin cell hyperplasia; gastric neuroendocrine tumors; gastritis; gastroenterology; gastrointestinal; hypergastrinemia; neuroendocrine tumors; pernicious anemia.

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Conflict of interest statement

Human subjects: Informed consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Endoscopic view of gastric body with patchy inflammation
Figure 2
Figure 2. Endoscopic view of normal gastroesophageal junction
See this image and copyright information in PMC

References

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