PICTURES IN DIGESTIVE PATHOLOGY

 

Pseudomelanosis duodeni: is there a common denominator?

 

 

Rosa Coelho¹, Armando Ribeiro¹, Roberto Silva², Elisabete Rios², Marco Silva¹ and Guilherme Macedo¹

Departments of ¹Gastroenterology and
²Pathology. Centro Hospitalar São João. Porto, Portugal

 

 

A 76-year-old female patient with a past medical history of diabetes mellitus, stage 3 chronic renal failure and iron deficiency anemia was referred for esophagogastroduodenoscopy (EGD) for evaluation of solid food dysphagia. She had been on oral therapy with ferrous sulfate for several years. Besides a Schatzki's ring the EGD revealed a duodenal mucosa with black-speckled pigmentation (Fig. 1). Biopsies were performed and disclosed the deposition of brown (hemosiderin) pigment within macrophages in the lamina propria of normal villi (Fig. 2). This endoscopic appearance is called pseudomelanosis duodeni (PD).

 

 

 

This rare but benign condition was first described in 1976, it has female predominance and occurs mostly in the sixth and seventh decades of life (1,2). The most common extracolonic site for pseudomelanosis of the gastrointestinal tract is the duodenum (1,2). Despite PD pathogenesis is still unclear, it has been associated with several illnesses, including end-stage renal disease, hypertension, diabetes mellitus, gastrointestinal hemorrhage and folic acid deficiency (3,4). Some medications have also been linked, such as sulfur-containing antihypertensive agents, furosemide and ferrous sulfate (4).

Although the cause and natural history of the pigment have not been clarified yet, it seems to correspond mainly to an accumulation of iron sulfide and hemosiderin within macrophages in the lamina propria. Likewise, there is no consensus regarding the nature and source of the pigment accumulation seen in the macrophages but it is thought to contain iron, sulfur, or melanin/melanin-like pigment (2).

In the literature, there are only few cases of PD described, and its etiopathogenesis remains unknown (1-4). Interestingly, in our patient three of the most important conditions (chronic renal failure, diabetes mellitus and history of oral iron supplementation) were also present. Therefore, this case could be a supportive finding regarding the definitive causative factor for this rare endoscopic condition.

 

References

1. Cantu JA, Adler DG. Pseudomelanosis duodeni. Endoscopy 2005;37:789. DOI: 10.1055/s-2005-870144.         [ Links ]

2. Castellano G, Canga F, López I, et al. Pseudomelanosis of the duodenum. Endoscopic, histologic, and ultrastructural study of a case. J Clin Gastroenterol 1988;10:150-4. DOI: 10.1097/00004836-198804000-00009.         [ Links ]

3. Magalhães Costa MH, Fernandes Pegado M, Vargas C, et al. Pseudomelanosis duodeni associated with chronic renal failure. World J Gastroenterol 2012;18:1414-6. DOI: 10.3748/wjg.v18.i12.1414.         [ Links ]

4. Kim SY, Choung RS, Kwon BS, et al. Small bowel pseudomelanosis associated with oral iron therapy. J Korean Med Sci 2013;28:1103-6. DOI: 10.3346/jkms.2013.28.7.1103.         [ Links ]