Metastatic calcification does not occurs in: March 2007
**Core Concept**
Metastatic calcification is a pathological process where calcium phosphate crystals deposit in otherwise normal tissues due to hypercalcemia, often seen in conditions like hyperparathyroidism, vitamin D toxicity, or malignancies.
**Why the Correct Answer is Right**
Metastatic calcification occurs when there is an excessive level of calcium in the blood, which leads to the precipitation of calcium salts in various tissues, including kidneys, lungs, and blood vessels. This process is mediated by the high concentration of calcium ions, which supersaturates the bodily fluids and facilitates the formation of calcium phosphate crystals.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because metastatic calcification can occur in any condition that leads to hypercalcemia, including hyperparathyroidism, which can cause excessive parathyroid hormone secretion, leading to increased calcium levels in the blood.
**Option B:** This option is incorrect because metastatic calcification is not limited to specific organs like the lungs; it can occur in any tissue that is exposed to high levels of calcium.
**Option D:** This option is incorrect because metastatic calcification is a distinct process from dystrophic calcification, which occurs in damaged or necrotic tissues.
**Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that metastatic calcification is often associated with conditions that lead to hypercalcemia, such as hyperparathyroidism or malignancies, and can be a diagnostic clue in these cases.
**Correct Answer: C.**