Peppered and rare – Gastric and Duodenal Pseudomelanosis: A case series

Abstract

Upper Gastrointestinal (GI) pseudomelanosis is an uncommon entity characterized by endoscopic visualization of speckled dark mucosal pigmentation. While described in the rectum and colon, ‘melanosis’ or more aptly ‘pseudomelanosis’ is rare in the duodenum and exceedingly rare in the stomach. Five cases of pseudomelanosis were encountered at our department. Four females and one male were diagnosed, with a mean age of 70 years. All patients exhibited duodenal pseudomelanosis, with one demonstrating gastric antral pseudomelanosis as well. Common features among these patients included iron deficiency anemia, hypertension, chronic kidney disease, hydralazine use and iron supplementation. Biopsy specimens stained at least partially positive for iron and stains for calcium and copper were negative. Histochemical analysis revealed the pigment of pseudomelanosis to be mainly iron sulfide, exhibiting unpredictable staining patterns, hypothesized to be secondary to varying sulfur content and iron oxidation. It is visualized as dark deposits in macrophages at the tips of the duodenal villi. Upper GI pseudomelanosis remains a poorly understood finding, weakly associated with chronic kidney disease, diabetes, hypertension, iron supplements and anti-hypertensive medications. While the pathogenesis, clinical and prognostic significance remains unclear, it is thus far considered a benign condition.

Pseudomelanosis intestini “from pylorus to jejunum:” A rare endoscopic finding in a patient with GI bleeding

“…[ 15 ] This has been hypothesized to be secondary to coupling of iron with sulfur or cyclic compounds, leading to the accumulation of the pigment within the mucosa, the source of sulfate is unclear; however, antihypertensive drugs such as hydralazine and foods that contain sulfate are thought to be the culprit. [ 16 ] Nonetheless, this does not explain the extra-duodenal sites of pigments or the association where sulfur containing ingestions are not found. This case is also unique because the pseudomelanosis pigmentation is not confined to areas in the GI tract with known iron absorption, and the distribution of pigmentation is much greater than most cases reported in the literature.…”

Rare Finding of Concomitant Pseudomelanosis of Stomach and Duodenum

“…These patients exhibited some of the following medical conditions: iron deficiency anemia, hypertension, chronic kidney disease, hydralazine use, and iron supplementation. Diagnoses of pseudomelanosis in these individuals were made based on biopsy specimens staining positive for iron but negative for calcium and copper ( 8 ).…”