Examples include nicotine stomatitis, which is keratosis in response to heat from tobacco smoking (rather than a response to the carcinogens in tobacco smoke). The risk of malignant transformation is similar to normal mucosa. Mechanical trauma, e.g. caused by a sharp edge on a denture, or a broken tooth, may cause white patches which appear very similar to leukoplakia. However, these white patches represent a normal hyperkeratotic reaction, similar to a callus on the skin, and will resolve when the cause is removed. Where there is a demonstrable cause such as mechanical or thermal trauma, the term idiopathic leukoplakia should not be used. Pathophysiology
Tumor suppressor genes
Tumor suppressor genes are genes involved in the regulation of normal cell turnover and apoptosis (programmed cell death). One of the most studied tumor suppressor genes is p53, which is found on the short arm of chromosome 17. Mutation of p53 can disrupt its regulatory function and lead to uncontrolled cell growth. Mutations of p53 have been demonstrated in the cells from areas of some leukoplakias, especially those with dysplasia and in individuals who smoke and drink heavily. Diagnosis
Definition
Leukoplakia is a diagnosis of exclusion, meaning that which lesions are included depends upon what diagnoses are currently considered acceptable. Accepted definitions of leukoplakia have changed over time and are still controversial. It is possible that the definition will be further revised as new knowledge becomes available.
Fibrosing colonopathy is a disease that arises in people with cystic fibrosis treated with high doses of pancreatic enzyme supplements. Symptoms are non-specific with abdominal pain, abdominal swelling, vomiting, and constipation.Risk factors include being young, prior surgery of the intestines, and the use of certain medications including corticosteroids and H2 blockers. It may appear similar to distal intestinal obstruction syndrome or inflammatory colitis such as Crohns disease.A maximum dose of 10,000 IU of lipase per kilogram per day is recommended for pancreatic enzyme supplementation to prevent this condition. More than 60 cases have been described as of 1999. The disease was suggested to be caused by methacrylic acid copolymer which is used as coating for delayed release of enzymes but there is no reliable evidence for that. == References ==