RESUMO
Pseudomelanosis duodeni (PD) is a rare dark speckled appearance of the duodenum associated with gastrointestinal bleeding, hypertension, chronic heart failure, chronic renal failure and consumption of different drugs. We report four cases of PD associated with chronic renal failure admitted to the gastroenterology outpatient unit due to epigastric pain, nausea, melena and progressive reduction of hemoglobin index. Gastroduodenal endoscopy revealed erosions in the esophagus and stomach, with no active bleeding at the moment. In addition, the duodenal mucosa presented marked signs of melanosis; later confirmed by histopathological study. Even though PD is usually regarded as a benign condition, its pathogenesis and clinical significance is yet to be defined.