A 67-year-old female patient with iron deficiency anaemia ho had been taking ferrous sulphate tablets for seven years as referred to our institution because of indigestion. Esophaogastroduodenoscopy showed tiny, diffuse, brownish spots in her uodenal bulb mucosa (Fig. 1A). Magnified endoscopic findings ith white light revealed brownish, finger-like villous formations ith smooth edges arranged normally. On magnifying narrowand imaging (NBI), the micro-surface structure of the villi became istinct with light blue crests visualized on their edges. However, he microvasculature architecture within the villi was not visile. Instead, dark reddish-brown pigmentation was noted under he villi epithelium (Fig. 1B). A biopsy was taken and histologic ndings were indicative of haemosiderosis. Macrophages, singly nd in small collections, contain brown-black pigment within lamna propria and iron stain was positive (Fig. 2A, 100×, H and E tain). A high magnification view of Prussian blue stained duodenal