abscess AE an immune system disorder AE which shows an enclosed collection of liquefied tissue, known as pus, somewhere in the body. Abscess is the result of the body's defensive reaction to foreign material. abscessus WEB: http://medical-dictionary.thefreedictionary.com/abscess HPO: HP_0002722 An abscess is a collection of pus (dead neutrophils) that has accumulated in a cavity formed by the tissue on the basis of an infectious process (usually caused by bacteria or parasites) or other foreign materials (e.g. splinters, bullet wounds, or injecting needles). It is a defensive reaction of the tissue to prevent the spread of infectious materials to other parts of the body. SIDER: C0000833 YH 10000269 immune system AE