Cell Injury-2 Pathology-PDF

Cell injury-2 Dr.Gehan Abdelmenam  Intended Learning Objectives Describe definition, causes, sites, significance and morphologic changes of fatty change. List types and causes of pigment disorders. Recall definition and types of pathologic calcification.  Fatty Ch...

Cell injury-2 Dr.Gehan Abdelmenam  Intended Learning Objectives Describe definition, causes, sites, significance and morphologic changes of fatty change. List types and causes of pigment disorders. Recall definition and types of pathologic calcification.  Fatty Change * Definition: abnormal accumulation of triglycerides within parenchymal cells. * Site:  liver, most common site which has a central role in fat metabolism.  it may also occur in heart as in anaemia or starvation (anorexia nervosa)  Other sites: skeletal muscle, kidney and other organs. 3 * Causes: 1. Toxins (most importantly: Alcohol abuse) 2. Diabetes mellitus 3. Protein malnutrition (starvation) 4. Obesity 5. Hypoxia 4 * The significance of fatty change:  Depends on the severity of the accumulation.  Mild: it may have no effect.  Severe: fatty change steatohepatitis cirrhosis 5 * Morphological features of fatty liver: *Grossly: Size: enlarged. Shape: preserved. Surface: smooth. Color: yellowish. Consistency: soft & greasy. Capsule: stretched (non-adherent). C/S: bulges out with rounded edges. 6 7 *Microscopically: The cells are swollen, the cytoplasm contains droplets of fat. Fat appears as empty vacuoles in Haematoxyline & Eosin stained sections but stained in frozen sections by fat stains e.g. Oil Red O stain. 8 9 10  Fatty liver; Oil Red O stain 11  Disorders of Pigmentation  A. Endogenous pigmentation I. Melanin pigment Melanin deficiency Melanin hyper pigmentation 1. Albinism 1. Prolonged exposure -Hereditary absence of tyrosinase enzyme. to sun. -Hair is white, skin, iris, 2. Chloasma(melasma): choroids are pink. 2. Leucoderma:white skin brown patches on face, patches due to melanin nipple & genitalia due to loss. Causes of leucoderma: increased estrogen level. - vitilligo 3.Freckles:brown spots -2ry to leprosy or syphilis. due to exposure to - Idiopathic ultraviolet rays with 13  Albinism 14 Leucoderma Freckles Chloasma NEVUS Melanoma 15  II. Lipochrome (lipofuscin) pigment It is a yellowish brown pigment, which is found normally in heart, liver, testis, seminal vesicles & adrenals. Increases in old age & in atrophic conditions e.g. Brown atrophy of the heart. 16  III. Hemoglobin-derived pigment Bilirubin Hemozoin Hemosiderin (haematin) Increases in increases in Increases in jaundice. Bilharziasis & hemosiderosis. malaria. +ve with Released from Prussian blue. the parasite, engulfed by macrophages in liver, spleen → parasitic pigmentation. 17  Jaundice 18  Hemosiderin H&E: golden brown pigment Prussian blue stain: blue 19 Exogenous Pigmentations 20 21  Pathological calcification It implies the abnormal deposition of calcium salts in tissues rather than bone and teeth. It has 2 types:  Dystrophic calcification:  When the deposition occurs in dead or dying tissues e.g. areas of necrosis or atherosclerotic patches.  it occurs with normal serum levels of calcium  Metastatic calcification:  The deposition of calcium salts in normal tissues  It almost always reflects hypercalcemia. 22  REFERENCES Robbins and Cotran Pathologic Basis of Disease, 9th edition, 2014 ( Kumar, Abbas, Aster) Robbins Basic Pathology 10th edition, 2017 ( Kumar, Abbas, Aster) Good luck