Pathology Quiz

Understanding Cell Death, Intracellular Accumulations, and Pathologic Calcification

Cell Death:

• Two types of cell death: apoptosis and necrosis
• Necrosis occurs when lysosomal enzymes enter the cytoplasm and digest the cell, resulting in leakage of cellular contents and inflammation
• Apoptosis is a programmed cell death with shrinkage of the cell, chromatin condensation, and DNA degradation without complete loss of membrane integrity
• Necrosis is mostly pathological, while apoptosis is mostly physiological

Necrosis:

• Morphological changes in necrosis take time to develop after cell death
• Cytoplasmic changes include increased eosinophilia and vacuolation
• Nuclear changes include karyolysis, pyknosis, and karyorrhexis
• Different patterns of tissue necrosis include coagulative, liquefactive, caseous, fat, and gangrenous necrosis

Apoptosis:

• Programmed cell death due to lack of growth factors or DNA/protein damage
• Activation of enzymes leads to degradation of nuclear DNA and proteins, but membrane remains intact
• Apoptotic cells are cleared by phagocytes without eliciting an inflammatory response
• Process can be initiated through extrinsic or intrinsic pathways

Intracellular Accumulations:

• Abnormal substances can accumulate inside cells due to metabolic derangements
• Examples include fatty change (steatosis), glycogen accumulation, and pigment deposition
• Lipofuscin, melanin, and hemosiderin are endogenous pigments, while anthracotic pigment is exogenous
• Pathologic calcification is abnormal deposition of calcium salts and can occur in dead or dying tissues (dystrophic calcification) or normal tissues (metastatic calcification)

Pathologic Calcification:

• Abnormal deposition of calcium salts, usually with smaller amounts of other minerals

• Dystrophic calcification occurs in dead or dying tissues, while metastatic calcification occurs in normal tissues with calcium metabolic abnormalities

• Calcium salts appear as fine white granules or clumps, often felt as gritty deposits

• Dystrophic calcification can occur in areas of necrosis, advanced atherosclerosis, or aging/damaged heart valvesCauses and Types of Calcification

• Calcification is a process in which calcium builds up in body tissues, causing them to harden and become less flexible.

• There are two main types of calcification: dystrophic and metastatic.

• Dystrophic calcification occurs in damaged or dead tissues, such as after a heart attack or in atherosclerotic plaques.

• Metastatic calcification occurs in normal tissues in association with hypercalcemia, which can be caused by various factors.

• The most important causes of hypercalcemia are increased secretion of parathyroid hormone and renal failure with phosphate retention.

• Parathyroid tumors and some malignant tumors can produce parathyroid hormone or parathyroid hormone-related protein, leading to hypercalcemia and metastatic calcifications.

• Vitamin D intoxication, bone diseases, and other factors can also cause hypercalcemia.

• Dystrophic calcification of the aortic valves is an important cause of aortic stenosis in the elderly.

• Metastatic calcifications can occur in various organs, such as the kidneys, lungs, and blood vessels.

• Calcifications can be detected by imaging studies, such as X-rays, CT scans, and ultrasound.

• Treatment of calcifications depends on the underlying cause and may include medications, surgery, or lifestyle changes.

• Prevention of calcifications involves controlling risk factors, such as high blood pressure, high cholesterol, and smoking, and maintaining a healthy lifestyle.