Gastritis. Light micrograph of a section through a stomach tissue, showing chronic gastritis (inflammation). This is characterised by disorganisation of the surface mucosa lining and its glands, with significant inflammatory infiltration of leucocytes (white blood cells) in the connective tissues. Gastritis is a result of chronic infection, commonly by the bacterium Helicobacter pylori, or with autoimmune disease, or from reflux of bile or chronic alcoholism. Magnification: x20 when printed 10 centimetres wide.