Metastatic calcification does not occurs in: March 2007
Ans. A: Fundal glands of intestineCalcification refers to the deposition of calcium salts in vital or dying/ dead tissues.The two classical types of calcification are dystrophic and metastatic.Dystrophic calcification refers to the deposition of calcium salts in dead or dying tissues.It occurs principally in areas of coagulative, liquefactive, caseous and/or fat necrosis that persist for rather long periods of time.Dystrophic calcification occurs in the presence of normal levels of serum calcium (around 10 mg/100 ml) and in the absence of derangement in calcium metabolism.The exact form that the calcium accumulates in is hydroxyapatite.Calcification in dead tissue:- Caseous necrosis in T.B. is most common site of dystrophic calcification.Liquefactive necrosis in chronic abscesses may get calcified.Fat necrosis following acute pancreatitis or traumatic fat necrosis in breasts results in deposition of calcium soaps.Infarcts may undergo D.C.Thrombi, esp. in veins, may produce phleoboliths.Haematomas in the vicinity of bones may undergo D.C.Dead parasites like schistostoma eggs show D.C.Congenital toxoplasmosis involving CNS visualised by calcification in infarct brain.Calcification in the degenerated tissueDense scars may undergo hyalinedegeneration and calcification.Atheroma in aoa and coronaries frequently undergo calcification.Cysts can show calcifcation.Calcinosis cutis is condition in which there are irregular nodular deposits of calcium salts in skin and subcutaneous tissue.Senile degenerative changes may be accompanied by calcification.Metastatic calcification refers to the deposition of calcium salts in vital tissues in association with a defect in calcium metabolism that is characterized by hypercalcemia. The usual causes of the hypercalcemia include Hyperparathyroidism, either primary or secondary,Vitamin-D intoxication,Deficiency of magnesium andHypercalcemia of malignancy.Metastatic calcification may occur widely throughout the body, but it is found principally in interstitial tissue of blood vessels, kidneys, lungs and gastric mucosa.Calcinosis is a term sometimes used to describe extensive metastatic calcification.Calciphylaxis is the process whereby calcium precipitates in tissues in response to a challenging agent such as iron.
Fundal glands of intestine
Renal tubules
Lungs alveoli
Blood vessels