ABSTRACT
Melanosis duodeni is an uncommon pathologic condition characterized by diffuse small black spots on the first and second portions of the duodenum. It occurs predominantly in elderly patients and is linked to chronic renal failure, use of antihypertensive drug and oral iron supplementation, and/or presence of gastric hemorrhage. We report a case of melanosis duodeni in a 60-year-old woman diagnosed with hypertension 20 years ago and chronic renal failure 6 years ago. She has taken antihypertensive drugs for many years. On endoscopy, speckled black pigmentation of duodenal mucosa was detected. Microscopically, this duodenal lesions showed numerous coarse pigments in macrophages confined within the lamina propria. By ultrastructural study, macrophages contained electron-dense granules admixed with lipofuscin-like material in residual bodies.