ABSTRACT
Necrosis implies cell death. If the necrosed tissues are disposed of, an ulcer ensues. Morphologically necrosis has been classified as liquefactive (most ulcers, wet gan grene), ischemic (infarcts, tissues are mummified-ghost cells), caseous (specific for tuberculosis), and necrobiotic (incomplete necrosis). Apoptosis refers to programmed cell death, and generally refers to normal tissue turnover. According to etiology, ulcers can be traumatic, inflammatory, ischemic, and infectious. Often more than one mechanism operates in producing an ulcer, for instance after trauma there is an inflammatory response that can enhance the death of some tissues. The newly formed ulcer can then become infected, which triggers more inflammation and cell death. All these processes can be compounded if there is poor circulation, as is often the case in leg ulcers of elderly patients.
