Pseudomelanosis duodeni: Associated with multiple clinical conditions and unpredictable iron stainability - a case series

Abstract

Pseudomelanosis duodeni is seen endoscopically as dark spots in the duodenal mucosa and is generally considered to be local deposition of iron from oral iron intake. However, pseudomelanosis duodeni may be identified histologically even before it becomes endoscopically evident; iron stainability within the mucosa is uneven and unpredictable, and multiple clinical conditions other than oral iron intake may be associated. We reviewed 17 adult patients with histologically detected pseudomelanosis duodeni, their endoscopic appearances, iron stainability, and clinical findings including oral iron and drug intake. Only 6/17 (35 %) had endoscopically apparent dark spots. Perl's iron stain was entirely positive in 18 %, partially positive in 64 %, and negative in 18 % of cases. History of oral iron was present in 76 % of patients, but other clinical conditions consistently associated were hypertension in 88 %, end stage renal disease in 59 %, and diabetes mellitus in 35 % of patients.

Untitled

“…One study found the classic endoscopic appearance was only present in 35% of pseudomelanosis duodeni cases. Iron stain tends to be positive but was found to be negative in 18% of pseudomelanosis duodeni cases in the same study [7].…”

“…Endoscopy typically shows speckled mucosal pigment, which is black to brown and spotty in distribution [6]. On pathology, there are pigment laden macrophages in the lamina propria of the involved stomach and segment of bowel [7,8]. Similar histology may be seen in malignant melanoma, hemosiderosis and charcoal ingestion.…”

“…Chronic oral iron therapy has been suggested as one possible etiology of pseudomelanosis, as has antihypertensive medication use [7,9]. Interestingly, iron has been noted to be coupled with sulfur within macrophages in pseudomelanosis patients, which has been postulated to disrupt normal iron transport [5].…”

“…Interestingly, iron has been noted to be coupled with sulfur within macrophages in pseudomelanosis patients, which has been postulated to disrupt normal iron transport [5]. Drugbased sources of sulfur, such as antihypertensives, and non-drug-based sources of sulfur are likely responsible for this finding [7]. Less progress has been made on how other risk factors contribute to gastric and duodenal pseudomelanosis.…”

Sesame-like Pigmentation in the Duodenum

“…1 Although no clear etiology has been described, there are several proposed mechanisms regarding pathogenesis, including impaired luminal transport of iron or intramucosal hemorrhage in patients with hypertension, chronic renal failure, chronic heart failure and diabetes mellitus. 2 In addition, certain drugs, including oral iron, hydralazine, propranolol, hydrochlorothiazide and furosemide, have also been associated with pseudomelanosis duodeni.…”