Extracellular degeneration

Transcription

1 Extracellular degeneration By Dr. Hemn Hassan Othman PhD, Pathology Fall /17/2017 1

2 Extracellular Degenerations I / Hyaline Degeneration (Hyalinization): The ward hyaline is derived from the Latin ward hyalos which means glass. The term hyalinization is a term used to describe the change from normal to variable degree of smooth eosinophilic appearance. The eosinophilia indicates the presence of protein.

3 Types of hyaline degenerations: 1. Connective tissue hyaline degeneration: It is the type of hyaline degeneration that takes place in connective tissues e.g.: 1. The hyalinization that takes place in the wall of arterioles suffering from arteriosclerosis. 2. Hyalinized scar. 3. Hyalinized atretic graffian follicles. Significant of C.T. hyaline: In arteriole suffering from arteriosclerosis, the hyalinization may cause rupture of the blood vessel wall.

4 Connective tissue hyaline degeneration

5 Hyalinized arteriole wall suffering from arteriosclerosis

6 Hyalinized glomerulus (right)

7 2. Keratohyaline degeneration: may be: Normal as in the keratinized stratified squamous epithelium of skin, rumen and esophagus of herbivorous. Pathological, in this condition, the keratin is found in either an increasing amount or in abnormal location; e.g. 1. Corn on foot. 2. Warts papilloma. 3. Squamous cell carcinoma. 4. Vitamin A deficiency. Significant of pathological keratohyaline: It may be interferes with absorption or secretion in the affected tissue.

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9 Warts

10 3. Hyaline casts: This term is applied to the smooth eosinophilic content of coagulated protein that seen in renal tubules in diseases in which protein leaks through damaged glomeruli. 4. Hyaline thrombi : This term is applied to the smooth shiny red capillary thrombi that seen in case of thrombosis.

11 Hyaline casts in lumen of the renal tubules appear as eosinophilic glassy proteinicious materials.

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13 II / Fibrinoid degeneration: Fibrinoid is an amorphous, bright eosinophilic material found particularly in the wall of blood vessels of various sized. Fibrin is a major component along with serum proteins, particularly immunoglobulin s. Pathogenesis of Fibrinoid degeneration: a) Formation of antigen-antibody complex on the wall of blood vessels. b) Activation of complement system. c) Combination of these two component cause severe injury to the vessel wall and leakage of plasma protein particularly fibrinogen in to the lesion.

14 These pictures showed the wall of an arteriole stained with H&E. The amorphous pink [eosinophilic] material in the wall is Fibrinoid.

15 III / Gout: It s the name of a disease that occurs when uric acid and urate crystals are deposited in tissue as result of defects in Purine metabolism. This condition tends to occur in joint spaces or on other serous membranes, such as pleura or peritoneum, or in the renal tubules. The condition is known in human and avian species and is named articular or visceral gout, according to the site of deposition. The crystals cause irritation, pain and chronic inflammation. Etiology of gout: Incomplete metabolism of Purine derivatives and High protein diets

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17 IV / Cholesterol Cleft: Cholesterol collect as crystals in tissue after severe injury or tissue damage or hemorrhage. The crystals have a characteristic appearance called clefts, and occur in picked-fence type groups. This condition is often found in case of xanthomatosis that result from massive accumulation of lipids in the macrophage, and in case some tumors.

18 Cholesterol cleft in atherosclerosis

19 Xanthomatosis

20 (V) Amyloid degeneration General features: a waxy amorphous substance (protein fibriles) composed essentially of an abnormal protein is deposited in the extracellular tissue.

21 Detection: Post-mortem organs: Lugol s iodine Amyloid: deep dark red Normal tissue: yellow

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23 Biopsy materials: Light Microscope (LM): H&E (routine stain): Amyloid appear pink eosinophilic (protein) Special stain (Congo red) Amyloid red to orange normal tissue pale pink in color

24 Amyloid Congo red stain

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26 Amyloidosis special stain (Toluidine blue)

27 Nature of Amyloid: Related to acute phase reactive protein, which appears in the serum in many inflammatory conditions or derived from fragments of immunoglobulin molecules.

28 Pathological effects AMYLOID DEPOSITION Pressure on adjacent cells Blood vessels Atrophy Narrowing Increased permeability Transudation of protein out of vessels

29 Amyloidosis may also occur in other circumstances, e. g. in tumors of endocrine glands producing polypeptide hormones. In old aged individual, minor deposits of amyloid may occur in the heart, brain and mainly around the eye; the amyloidogenic protein in these cases is related to albumin deposition.

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31 Types of Amyloidosis: 1. Acquired systemic Amyloidosis; In this type there is abnormal production of immunoglobulin unrelated to any infectious process. Tumor or abnormalities of plasma cells in bone marrow are causes in this type. 2. Reactive acquired Amyloidosis; This type result from chronic infectious diseases. 3. Organ limited Amyloidosis; particularly in the skin, heart and cerebrum, which seems to occur without an obvious cause (Aging). 4. Localized Amyloidosis; Caused by localized tumors of plasma cells in various tissues.

32 Significant of Amyloidosis: Amyloid deposits acts as space occupying lesion in hepatic sinusoids, interfering with hepatic function. It can cause pressure atrophy and marked disturbances of normal physiological functions of vital organs which lead to clinical diseases and death. Amyloidosis is best known as a primary cause of uremia (Kidney). It is a cause of Diabetes Mellitus when it replaces pancreatic islets. It s a cause of immune response interference when it replaces the splenic white pulp.

33 Organ: Heart Lesions: 1.Deposition of an amorphous, homogenous, eosinophilic material (black arrows) extracellularly among the myocardial muscle fibers (A). 2.The Congo red stain shows pinkish coloration of the deposited material (B). Diagnosis: Amyloidosis A B

34 Organ: Pancreas Lesion: Deposition of an amorphous, homogenous, eosinophilic, material (black arrow) extracellularly within the glandular tissue. Diagnosis: Amyloidosis

35 Pathologic calcification Definition: Abnormal deposits of calcium salts occur in any tissues except bones and teeth.

36 Type: 1 Dystrophic calcification: Local deposits of calcium may occur in: Necrotic tissue (dead tissue). Tissues undergoing slow degeneration (Atherosclerosis or Tuberculosis).

37 2 Metastatic calcification: This alteration may occur in normal tissues whenever there is hypercalcemia. The causes of hypercalcemia include hyper Parathyroidism, vitamin D intoxication, hyperthyroidism Addison s disease. Metastasis calcification may occur widely throughout the body but principally affects the interstitial tissues of the blood vessels, heart valves, kidneys, lungs, and gastric mucosa.

38 View looking down onto the unopened aortic valve in a heart with calcific aortic stenosis.

39 calcification

40 calcification