This document discusses pathological calcification, which occurs when calcium salts abnormally deposit in tissues other than bones and teeth. There are two types: dystrophic calcification, which occurs in dead or damaged tissues; and metastatic calcification, which occurs in normal tissues due to disorders of calcium metabolism. Metastatic calcification is usually reversible if the underlying metabolic disorder, such as hyperparathyroidism or hypercalcemia from kidney failure, is corrected. Common sites of metastatic calcification are the kidneys, lungs, blood vessels, stomach, and cornea. Under the microscope, calcium salt deposits appear as basophilic granular clumps that can be confirmed with special staining techniques.

1. PATHOLOGICAL
CALCIFICATION
SUBMITTED TO:
Rajesh Sir
Pathology
Veterinary(B.V.Sc.&A.H)
AFU,Rampur
SUBMITTED BY:
Suman Bhattarai
Roll NO : 50(Fiftty)
Rampur,Chitwan,Nepal

2. PATHLOGICAL CALCIFICATION:
►Abnormal deposits of calcium salts occur in any tissues except bones and teeth
►With smaller amount of iron,magnesium and other mineral salts
2 distinct types
Dystrophic Calcification Metastatic calcification
Characterised by deposition of calcium salts
In dead or degenerated tissue
Normal calcium metabolism
Normal serum calcium
levels
Characterised by deposition of calcium salts
In apparently normal tissue
De-ranged calcium metabolism
Hypercalcaemia

3. Metastatic calcification
Reversible upon correction of metabolic disorder
Hypercalcaemia ( more than 12mg % )
May be due to the
Excessive mobilization of calcium from the bone
Excessice absorption of calcium from the gut
1)Excessive mobilization of calcium from bone:
A) Hyperparathyroidism
1.Primary
-Parathyroid adenoma
2.Secondary
-Parathyroid hyperplasia
-Chronic renal failure

4. Hyperparathyroidism
Associated with parathyroid
neoplasm
Increased parathyroid activity removes calcium from bones
i.e.Demineralization of bones .that become rarefied and a large cyst
Like spaces appear within them
Resultant hypercalcaemia leads to metastatic calcification

5. Renal Failure
Leads to phosphate retention
Causes increased activity of parathyroid gland
Called as Secondary hyperparathyroidism
Dimineralization of bones
Metastatic Calcification

6. B.Bony Destructive Lesions
-Multiple Myeloma
-Metastatic Carcinoma
-Leukemia
MYELOID TUMORS IN BONE MARROW
+
METASTATIC CANCER
causes
Demineralization of Skeleton
Blood stream is flooded with calcium

7. C. Prolonged Immobilisation
Disuse atrophy of the bones and hypercalcaemia
2.Excessive Absorption of calcium from the gut
A. Hypervitaminosis D
B. Milk Alkali Syndrome
-Excessive oral intake of calcium in form of milk
-Administration of calcium carbonate in treatment of peptic ulcer
C. Hypercalcaemia of infancy
D. Sarcoidosis
-Macrophages active a vitamin D precursor

8. Sites of Metastatic calcification
May occur in any normal tissue of body especially in those tihat
secrete or excrete acid substances.
Affected organs more commonly are:
1. Kidneys:(Secretes Hippuric acid)
Especially at basement membrane of tubular epithelium and
in tubular lumina causes nephrocalcinosis.
2.Lungs(C02)
especially in alveolar walls
3.Stomach(HCL)
On acid secreting fundal glands(gastric mucosa)
4.Blood Vessels
Especially on internal elastic lamina
5.Cornea
6.Synovium of joint causing pain and dysfunction

11. Pathogenesis:
Excessive binding of inorganic phosphate ions with the calcium ions i.e increased
Precipitates of Ca-phosphate due to hypercalcaemia at certain sites.
Eg.in lungs,stomach ,blood vessels and cornea.
Morphologically
-Ca-salts in all these sites, resembles those described in dystrophic calcification
-Etiology and pathogenesis of two are different
-Morphologically the deposits in both resemble normal minerals of bone.
H & E Stained Sections (Haematoxylin and eosin )
Macroscopy-
Microscopy-
Can vary in size,white granules which may be gritty.
-Ca-salts appear as deeply basophilic,irregular and granular clumps
-Depositss may be intracellular,extracellular or both.
-Occassionally ,heterotopic bone formation(ossification) may occur.
-Calcium deposits can be confirmed by special stains
_Silver Impregnation method of von-kossa producing black colour
_Alizarin red S that produces red staining

12. -Pathologic calcification is often accompanied by diffuse or granular deposits of iron
_Positive: Prussian blue reaction in perl;s stain
Significance & Results
Calcification in itself is usually not harmful and causes no clinical dysfunction
Occasionally,it may impair organ;s Motility
EG: Massive deposit in kidney(nephrocalcinosis) may cause renal damage
Calcium disappears from tissue when primary cause
Is removed