Light micrograph of haemosiderin pigment (dark brown clumps) that has been ingested by macrophages (pink circles), a type of immune cell. The haemosiderin originates from metabolism of haemoglobin from extravasated red blood cells (light red circles in the background). Haematoxylin and eosin stained tissue section. Magnification: x400 when printed at 10cm wide.