A 50-year-old man has megaloblastic anemia and subacute combined degeneration of the spinal cord. Anti-intrinsic factor antibodies are positive. The gastric lesion underlying this condition is:

• A Antral-predominant H. pylori gastritis causing reduced acid secretion
• B Celiac disease-like enteropathy of the terminal ileum preventing B12 absorption
• C Autoimmune corpus-predominant atrophic gastritis with achlorhydria and absent intrinsic factor ✓
• D Zollinger-Ellison syndrome with excessive acid inactivating intrinsic factor

Explanation

Pernicious anemia results from autoimmune destruction of gastric parietal cells (corpus-predominant atrophic gastritis), causing achlorhydria and absent intrinsic factor secretion; without IF, dietary B12 cannot be absorbed in the terminal ileum. Anti-parietal cell and anti-intrinsic factor antibodies are the serological markers. H. pylori gastritis is antral-predominant; terminal ileum disease causes B12 malabsorption without anti-IF antibodies; ZES causes excess acid, not IF deficiency.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.