Tumor - Causes

Causes

A neoplasm can be caused by an abnormal proliferation of tissues, which can be caused by genetic mutations. Not all types of neoplasms cause a tumorous overgrowth of tissue, however (such as leukemia or carcinoma in situ).

Recently, tumor growth has been studied using mathematics and continuum mechanics. Vascular tumors are thus looked at as being amalgams of a solid skeleton formed by sticky cells and an organic liquid filling the spaces in which cells can grow. Under this type of model, mechanical stresses and strains can be dealt with and their influence on the growth of the tumor and the surrounding tissue and vasculature elucidated. Recent findings from experiments that use this model show that active growth of the tumor is restricted to the outer edges of the tumor, and that stiffening of the underlying normal tissue inhibits tumor growth as well.

Benign conditions that are not associated with an abnormal proliferation of tissue (such as sebaceous cysts) can also present as tumors, however, but have no malignant potential. Breast cysts (as occur commonly during pregnancy and at other times) are another example, as are other encapsulated glandular swellings (thyroid, adrenal gland, pancreas).

Encapsulated hematomas, encapsulated necrotic tissue (from an insect bite, foreign body, or other noxious mechanism), keloids (discrete overgrowths of scar tissue) and granulomas may also present as tumors.

Discrete localized enlargements of normal structures (ureters, blood vessels, intrahepatic or extrahepatic biliary ducts, pulmonary inclusions, or gastrointestinal duplications) due to outflow obstructions or narrowings, or abnormal connections, may also present as a tumor. Examples are arteriovenous fistulae or aneurysms (with or without thrombosis), biliary fistulae or aneurysms, sclerosing cholangitis, cysticercosis or hydatid cysts, intestinal duplications, and pulmonary inclusions as seen with cystic fibrosis. It can be dangerous to biopsy a number of types of tumor in which the leakage of their contents would potentially be catastrophic. When such types of tumors are encountered, diagnostic modalities such as ultrasound, CT scans, MRI, angiograms, and nuclear medicine scans are employed prior to (or during) biopsy and/or surgical exploration/excision in an attempt to avoid such severe complications.

The nature of a tumor is determined by imaging, by surgical exploration, and/or by a pathologist after examination of the tissue from a biopsy or a surgical specimen.

Read more about this topic:  Tumor

Other articles related to "causes, cause":

Local Anesthetic - Undesired Effects - Localized Adverse Effects - Causes
... Causes of localized symptoms include neurotoxicity due to allergenic reaction, excessive fluid pressure in a confined space, severing of nerve fibers or support tissue with the ...
Writer's Cramp - Causes
... is often observed in other body parts use of the right hand may cause pain and cramping in that hand as well as in the other hand and legs that were not being used ...
Era Of Stagnation - Economy - Causes
... One of the suggested causes of stagnation was the increased military expenditure over consumer goods and other economic spheres ... argue that militarisation cannot be the prime cause for the economic stagnation, as military spending had historically been high (17% of GNP in 1950) and had increased on par with economic ...