An exudative appearance is seen in this endoscopic image of the gastric mucosa.
At low power, brown material can be appreciated along an abnormal gastric mucosa. The material is most often extracellular and represents oxidized inorganic iron and is refractile but not polarizing. Sometimes iron containing thrombi may be seen in small vessels.
There is an erosion with fibrin deposition and scattered neutrophils replacing the surface mucosa associated with the brown material. Gastric erosion can arise within hours of iron pill ingestion, thought to act as a direct corrosive agent.
Hi power illustrates the crystalline material is distributed along the surface as well as within the epithelial cells below. Material can be found both within the glands and lamina propria in such cases.
Iron in gastrointestinal biopsy specimens is associated with iron overload conditions- hemochromatosis, recurrent transfusions, and oral iron supplementation. End stage liver disease is another underlying cause for this finding.
An abnormal biopsy can be found as early as within a few days of initiating oral iron supplementation. It remains unceratin as to why inorganic (nonheme) iron bypasses normal absorption pathways and deposits in the upper GI tract mucosa as a crystalline substance. The absorption and regulation of iron occur through an energy-dependent, carrier-mediated system.
While the duodenum is the most active site of iron absorption, the stomach, ileum, and colon may also participate. In the stomach, luminal mucin and acidic pH help with to inorganic iron absorption.
Many patients have underlying infectious, mechanical, toxic, or systemic medical conditions that potentially initiate or exacerbate the injury. Presentations include coffee-ground emesis and melena.
Mucosal injury can occur in patients taking therapeutic doses of oral iron supplementation.
Haig A, Driman DK. Iron-induced mucosal injury to the upper gastrointestinal tract. Histopathology. 2006;48(7):808-12.
Abraham SC, Yardley JH, Wu TT. Erosive injury to the upper gastrointestinal tract in patients receiving iron medication: an underrecognized entity. Am J Surg Pathol. 1999;23(10):1241-7.