Pseudomelanosis Gastri: A Case Report

Introduction: Pseudomelanosis is likely due to deposition of pseudomelanin, the byproduct of pigment degeneration by lysosomes, in mucosal tissue as dark pigments. In this case report, we present a rare case of gastric pseudomelanosis, antral subtype, in a 77-year-old female with multiple associated comorbidities, we then further discuss the similarities and differences of our case with the reported cases in the literature. Case Presentation: 77 year old Caucasian female with worsening epigastric pain and nausea. Imaging showed gastric wall thickness. Prior endoscopy 6 months prior, showed gastritis. Last colonoscopy 2 years prior, no abnormal findings. Medical history included diabetes mellitus, hypertension, and iron deficiency anemia. Medications included hydralazine, amlodipine, losartan and oral iron supplements. Underwent repeat upper endoscopy, showing moderate melanotic mucosa in the antrum, in linear fashion. Biopsies showed pigment deposits, negative for iron stain. Normal appearing duodenum, without lesions. Deviation from Expected: The biopsies in this case were did not stain for iron, and were located in the antrum, which is a less common site (23%), pylorus being more common (67%). Discussion: Only a 21 cases of gastric pseudomelanosis have been reported in English literature. Females compose 75% of reported cases. Associated with anti-hypertensive and iron-containing medications. Conclusion: Pseudomelanosis is also associated with a variety of common clinical pathologies such as hypertension, chronic renal disease, and diabetes mellitus. Although relatively rare and benign, with the increasing number of reported cases, it is crucial for gastroenterologists to have pseudomelanosis on their differential list.