Definition

Pathological Calcification is a common process in a wide variety of disease states, it implies the abnormal deposition of Calcium salts, together with small amounts of iron,Mg and other minerals.

Types of Calcification

Dystrophic CalcificationMetastatic Calcification

Dystrophic Calcification When deposition occurs in dead or

dying tissues, it is dystrophic calcification. It occurs in absence of calcium metabolic derangements (i.e. with normal serum levels of calcium)

Etiology of Dystrophic CalcificationDystrophic Calcification can develop in

Aging or damaged heart valvesAged pineal glandDead parasitesDead retained FetusAtheromas Areas of NecrosisCarcinomas

Morphology of Dystrophic CalcificationRegardless of sight, Ca salts are grossly seen as fine white granules or clumps, of ten felt as gritty deposits. Sometime a tuberculous lymph node is essentially converted to radio opaque stone.

(contd….)Calcium appears in intracellular or extracellular basophilic deposits.

Hypertrophic bone may be formed in the focus of calcification.

Pathogenesis of Dystrophic Calcification

INITIATION

Calcium from mitochondria

Calcium combines with phospholipids in cell membrane

Membrane associated phosphatases generate phosphate groups that bind to bound Ca

Pathogenesis of Dystrophic Calcification

PROPAGATION

Cycle of Ca and PO4 binding is repeated again and again

Micro crystals develop after rearrangement in PO4 and Ca ions

Dystrophic Calcification

Metastatic Calcification The deposition of Calcium salts in

normal tissues is known as Metastatic Calcification.

Metastatic Calcification can occur in normal tissue whenever there is hypercalcaemia.

Etiology of Metastatic CalcificationIncreased secretion of Parathyroid hormone with subsequent bone

resorption seen in:

a) Hyperparathyroidism due to PH tumors

b) Ectopic secretion of PH by malignant tumorsDestruction of bone tissue seen with:

a) Primary tumors of bone marrow like multiple myeloma & leukemis

b) Diffuse skeletal metastasis

(contd….)

Renal failure causes retention of PO4 leading to secondary hyperparathyroidism.

Vitamin D related disorders:

a)Vitamin D intoxication

b) Sarcoidosis

Morphology of Metastatic CalcificationMetastatic calcification can occur widely throughout the body but principally affects the interstitial tissues of vasculature, kidneys,

lungs and gastric mucosa. The Ca deposits morphologically

(Contd…..)resemble those described in dystrophic calcification

Although they do not, generally, cause clinical dysfunction, extensive calcifications in the lungs may produce remarkable

(Contd…..)radiographs & respiratory deficits and massive deposits in the kidney (nephrocalcinosis) can cause renal damage.

Pathogenesis of Dystrophic Calcification

It is related to traveling tumors from one place in body to other.

In some cases we have extensive bone destruction and this is mainly in METASTATIC BONE CANCERS. Many cancers -in there last stages- deposit some of the malignant tumor outside the original organ, like breast, prostate or thyroid tumor. Part of the tumor will go by the blood stream or the lymphatic’s to spread and destroy the bone and (Ca+2) will be released.

Abnormal intracellular depositions and calcifications

1) Deposition of Lipids

a) Fatty change: Accumulation of free triglycerides in cells resulting from excessive intake or defective transport ;manifestation of reversible cell injury.

b) Cholesterol deposition: Result of defective catabolism and excessive intake, in macrophages and smooth muscle cells of vessel walls in atherosclerosis.

2) Deposition of Proteins a) Reabsorbed proteins in kidney tubules.

b) Immunoglobulins in plasma cells.

(Contd…..) 3) Deposition of Glycogen

Deposition of glycogen in macrophages of patients with defects in lysosomal enzymes that break down glycogen (Glycogen storage disorders).

4) Deposition of Pigments Indigestible pigments such as carbon, lipofuscin (breakdown product of

lipid peroxidation),iron (due to overload as in hemosidrosis ).

Effects of CalcificationHeart Certain type of cancerous tumors and tissue damage that causes

atherosclerosis or clogged, hardened arteries that result in heart attack.

Brain

Calcifications found in arteries that lead to brain such as those in neck and spine can cause a stroke.

Breasts Calcifications is most often benign but in some cases may indicate

malignancy.

(Contd…..)Joints

Joints become inflamed, painful and their movements become limited.

Cartilage

Calcium crystals lead to erosion of cartilage.

Kidney IF calcium kidney stones are large or have jagged edges, they can cause

extreme pain as they travel through the urinary tract and may cause a blockage that can lead to kidney failure.