Introduction to Pathology PDF

Introduction to Pathology Dr.Gehan Abdelmenam  Intended Learning Objectives Recall definition of pathology. List different classifications of pathology. Describe Classification of Diseases. List Items of study of any disease with explanation of each item. List different methods...

Introduction to Pathology Dr.Gehan Abdelmenam  Intended Learning Objectives Recall definition of pathology. List different classifications of pathology. Describe Classification of Diseases. List Items of study of any disease with explanation of each item. List different methods for obtaining biopsy  Pathology: is the science which studies the nature of the disease. Pathology Classification: 1-General pathology:The study of general reactions of cells and tissues to injuries that are basic to all disease processes. 2. Systemic pathology:The study of specific disease processes or reactions as they affect particular organs or organ systems e.g. CVS, CNS, GIT…..etc.  Applied Classification of pathology: 1. Necropsy pathology:Examination of tissues excised from cadavers in an effort to establish the cause of death. – This is called “autopsy”. 2. Surgical pathology: Examination of tissues excised from living patients in an effort to establish a specific diagnosis. – This is called “biopsy”.  Biopsy - Examination of tissues from the living body to determine the cause of a disease. 1. Needle or core biopsy: – The pathologist or clinician put a needle into the mass to obtain a bit of tissue. – Usually won’t give you enough material. 2. Incisional biopsy: - An incision was made to obtain a larger mass of tissue. 3. Excisional biopsy: - Excision of the whole mass for diagnosis. Needle or core biopsy Excisional biopsy Incisional biopsy Classification of pathology according to type of examined specimen: 1. Histopathology: Examination of tissues in an effort to establish a specific diagnosis. 2. Cytopathology:The microscopic study of exfoliated cells within body fluids. Fine needle aspiration cytology (FNAC)  Cytolopathology FNAC = Fine Needle Aspiration A thin core needle is used to obtain a few cells from Cytology a mass lesion. Used for: – Superficial mass – Deep mass lesions (with help of radiology)  The Disease: The structural and functional changes in organs and tissues due to exposure to an irritant (causative agent of the disease).  * Classification of Diseases: A. Hereditary: diseases caused by chromosomal abnormality or gene mutation. B. Acquired: 1. Inflammatory. 2. Neoplastic e.g. Tumors 3. Degenerative e.g. Aging. 4. Metabolic.  Items of study of any disease include: 1. Definition. 2. Etiology. 3. Pathogenesis. 4. Morphological features. 5. Complications. 6. Prognosis.  Etiology of Disease: Means the cause of a disease" a. Predisposing Causes of Disease: Factors which make an individual more susceptible to a disease (heredity, low immunity…) b. Exciting Causes of Disease: Factors which are directly responsible for the disease e.g. infection,.. ).  Pathogenesis of the disease The mechanism by which the etiologic agent causes the disease.  MORPHOLOGY 1. Gross (macroscopic) picture: examination of the tissue by naked eye. 2. Microscopic picture: examination of the tissue sections by light microscope.  1. Gross picture: Size. Shape. Weight. Color. Consistency. Surface. Cut section. 2-Microscopic picture: Examination of the diseased tissues to specify the nature of the disease. Normal liver Fatty liver Hemangioma  Complications of the disease The added pathological changes during of after termination of the usual course of the disease. Examples: 1. Common cold complicated by acute bronchitis. 2. Acute bronchitis complicated by pneumonia.  Prognosis of the disease Expected outcome (fate) of the disease. – Good prognosis: suggests that the recovery is more likely. – Poor prognosis: suggests that permanent disability or death is more likely.  REFERENCES Robbins and Cotran Pathologic Basis of Disease, 9th edition, 2014 ( Kumar, Abbas, Aster) Robbins Basic Pathology 10th edition, 2017 ( Kumar, Abbas, Aster) Welcome to Pathology