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  • Preface

    1. 1. Chapter One Introduction to Pathology Section A What is pathology?
    2. 2. Definition of Disease <ul><li>Disease may be defined as an abnormal alteration of structure or function in any part of the body. </li></ul>
    3. 3. Classification of Diseases: <ul><li>Developmental – genetic, congenital. </li></ul><ul><li>Inflammatory – Trauma, infections, immune, etc. </li></ul><ul><li>Neoplastic – tumors, cancers </li></ul><ul><li>Degenerative – ageing. </li></ul>
    4. 4. Pathology <ul><li>Study of what is abnormal or wrong or disease…! </li></ul><ul><li>“ Scientific Study of Disease” </li></ul><ul><li>Normal  Abnormal  Treat </li></ul>
    5. 5. Study of Disease: <ul><li>Epidemiology </li></ul><ul><li>Etiology - Causes </li></ul><ul><li>Pathogenesis - Evolution </li></ul><ul><li>Morphology - Structural Changes </li></ul><ul><li>Clinical Significance – Functional Changes </li></ul><ul><li>Clinical manifestation </li></ul><ul><li>Complications </li></ul><ul><li>Prevention </li></ul>Pathology
    6. 6. Pathology focuses on 4 aspects of disease <ul><li>ETIOLOGY: Cause of disease. </li></ul><ul><li>PATHOGENESIS: </li></ul><ul><li>Mechanisms of development of disease. </li></ul><ul><li>MORPHOLOGY: The structural alterations induced in cell and tissues. </li></ul><ul><li>FUNCTIONAL CONSEQUENCES: </li></ul><ul><li>Functional consequences of the morphologic changes, as observed clinically. </li></ul><ul><li>Knowledge of etiology remains the backbone: </li></ul><ul><li>Disease diagnoses </li></ul><ul><li>Understanding the nature of diseases </li></ul><ul><li>Treatment of diseases. </li></ul>
    7. 7. Etiology: <ul><li>Environmental agents: </li></ul><ul><ul><li>Physical </li></ul></ul><ul><ul><li>Chemical </li></ul></ul><ul><ul><li>Nutritional </li></ul></ul><ul><ul><li>Infections </li></ul></ul><ul><ul><li>Immunological </li></ul></ul><ul><ul><li>Psychological </li></ul></ul><ul><li>Genetic Factors: </li></ul><ul><ul><li>Age </li></ul></ul><ul><ul><li>Genes </li></ul></ul>Multifactorial:
    8. 8. <ul><li>One etiologic agent—one disease. </li></ul><ul><li>Several etiologic agents—one disease. </li></ul><ul><li>One etiologic agent—several diseases. </li></ul>
    9. 9. <ul><li>Diseases are “caused” due to internal or external factors. </li></ul><ul><li>Multifactorial: </li></ul><ul><ul><li>No more “one cause to one disease” </li></ul></ul><ul><li>Genetic factors affect acquired diseases and environment has profound effect on genetic diseases. </li></ul>
    10. 10. Pathogenesis: <ul><li>“Sequence of events in the response of cells & tissues to a stimulus/pathogen” starting from the initial stimulus to the ultimate expression of disease.” </li></ul><ul><li>Gross and microscopic Structure, Function, Chemistry & molecular mechanisms. </li></ul>
    11. 11. Pathogenesis <ul><li>The sequence events in the response </li></ul><ul><li>of the cells or tissues to the etiologic agent, from the initial stimulus to the ultimate expression of the disease. </li></ul>
    12. 12. Pathogenesis Immunologic, cytogenetic and molecular analyses of tissues and cells are increasingly becoming guides to render diagnoses, to assess prognosis, and to suggest therapy.
    13. 13. <ul><li>W hile much still needs to be uncovered to link abnormal genes and the expression of disease, gone are the time when the mechanisms of most diseases were unknown? or obscure? or mysterious? </li></ul>
    14. 14. <ul><li>Morphologic change </li></ul><ul><li>Characteristic of the disease </li></ul><ul><li>Diagnostic of the etiologic proceess </li></ul><ul><li>Functional derangements </li></ul><ul><li>Clinical significance </li></ul>MORPHOLOGY Morphology remains at the heart of diagnostic pathology.
    15. 15. Morphology: <ul><li>Structural and associated functional changes in cells, tissues and organs that are characteristic of the disease or condition. </li></ul>
    16. 16. Renal Infarction
    17. 19. Normal glomerulus
    18. 20. Membranous GN
    19. 21. Clinical Significance: <ul><li>Functional derangements and its clinical manifestations resulting from the morphologic changes. </li></ul><ul><li>Signs and symptoms, course and prognosis of disease depend on the morphology. </li></ul>
    20. 22. Pathology Summary: <ul><li>Etiology : </li></ul><ul><ul><li>Carcinogenesis. DNA Damage, Mutation. </li></ul></ul><ul><li>Pathogenesis : </li></ul><ul><ul><li>Uncontrolled cell division, tumor. </li></ul></ul><ul><li>Morphology : </li></ul><ul><ul><li>Enlarged lymphnodes, liver, spleen, microscopically – lymphoma cells. </li></ul></ul><ul><li>Clinical Features : </li></ul><ul><ul><li>Fever, Wt loss, tumor-Ln, Liver, Spleen. </li></ul></ul>
    21. 23. Section B What do pathologists do?
    22. 24. <ul><li>Human Pathology </li></ul><ul><li>Experimental Pathology </li></ul>Scope of Pathology
    23. 25. <ul><li>Human Pathology </li></ul><ul><li>Autopsy </li></ul><ul><li>Biopsy </li></ul><ul><li>Cytology </li></ul>
    24. 26. <ul><li>Autopsy </li></ul><ul><li>The internal examination of the body after death performed scientifically for medical or legal purposes. </li></ul>
    25. 32. <ul><li>Roles: </li></ul><ul><li>to clarify the nature of many diseases. </li></ul><ul><li>to determine the cause of death and to collect evidence </li></ul><ul><li>to gather accurate statistics about disease incidence </li></ul>
    26. 33. <ul><li>Biopsy </li></ul><ul><li>to establish a precise diagnosis by the removal and examination of tissue from the living body. </li></ul>
    27. 34. Tissue sections are embedded with paraffin.
    28. 35. stony hard lump or mass on palpation
    29. 37. Diagnosis: Carcinoma of the breast The invasive duct carcinoma usually has an abundant fibrous stroma, so it is also refered to as scirrhous carcinoma. Dense collagenous background
    30. 38. <ul><li>3 ) Cytology </li></ul><ul><li>Single cells or clumps of cells exfoliated from their surrounding tissues. </li></ul><ul><li>Sputum, urine and abdominal fluid </li></ul>
    31. 39. Sputum smears of cytology
    32. 40. Pap smear of CIN-III Large hyperchromatic nuclei, nuclear pleomorphism .There are some interspersed neutrophils with lobated nuclei and much smaller size.
    33. 41. Diagnosis <ul><li>What is “Diagnosis”? </li></ul><ul><ul><li>The formal name(s) used to describe a patient’s disease </li></ul></ul><ul><ul><li>The process of identifying a disease based on the patient’s symptoms, the doctor’s findings, and the results of investigations and laboratory tests </li></ul></ul><ul><li>What do you need to make a diagnosis? </li></ul><ul><ul><li>A system of classification that supplies the necessary names, definitions, and criteria </li></ul></ul><ul><ul><li>The means to ascertain the defining characteristics of a disease in the individual patient </li></ul></ul>
    34. 42. Sample Case:
    35. 43. Clinical Details: <ul><li>34 year , male </li></ul><ul><li>Neck swelling, 2-3 months, </li></ul><ul><li>Fever, weight loss, </li></ul><ul><li>no other lymphadenopathy </li></ul><ul><li>Lymphnode biopsy done </li></ul>
    36. 44. Right neck mass
    37. 45. Lymphnode Biopsy <ul><li>Diffuse tumour </li></ul><ul><li>Capsule </li></ul>
    38. 46. Lymphnode Biopsy <ul><li>Large cells </li></ul><ul><li>Mitotic figures </li></ul>
    39. 47. Histiocytic/Tcell NHL <ul><li>Diffuse pattern – no follicles. </li></ul><ul><li>Large cells with moderate cytoplasm </li></ul><ul><li>Plenty of mitotic figures, Nuclei are vesicular prominent nucleoli </li></ul><ul><li>Features suggest T-cell NHL – malignant lymphoma. </li></ul><ul><li>Needs further marker studies for typing & management. </li></ul><ul><li>cancer Chemotherapy. </li></ul>
    40. 48. <ul><li>Experimental Pathology </li></ul>In vitro: Tissue culture Organ culture Cell culture In vivo: Experimental animals Nude mice
    41. 49. <ul><li>Cell and tissue culture : </li></ul><ul><li>cellular environment can be modified and the responses to it monitored. </li></ul>
    42. 50. <ul><li>Animal experiments : </li></ul><ul><li>to observe the effect of manipulations on the animal model of disease . </li></ul>
    43. 52. Nude mice
    44. 53. Section C How do pathologists do?
    45. 54. RESEARCH METHODS <ul><li>Macroscopic observation </li></ul><ul><li>Microscopic observation (HE) </li></ul><ul><li>EM </li></ul><ul><li>Immunohistochemistry </li></ul><ul><li>Hybridization </li></ul><ul><li>Cell Cultures, Medical Microbiology </li></ul><ul><li>Molecular Pathology PCR </li></ul><ul><li>Flow cytometry </li></ul>
    46. 55. <ul><li>Gross Investigation </li></ul><ul><li>Size </li></ul><ul><li>Shape </li></ul><ul><li>Color </li></ul><ul><li>Weight </li></ul><ul><li>Morphologic features </li></ul>
    47. 56. <ul><li>Congestive Splenomegaly: the volume of the spleen is increased and swollen, red-brown. Irregular tan-white fibrous plaques can be seen over the purple surface. </li></ul>
    48. 57. Renal Infarction
    49. 62. <ul><li>Histopathological and Cytopathological Investigation </li></ul><ul><li>The microscopic examination of tissue and cell samples with LM on H.E. sections or smears. </li></ul><ul><li>Frozen sections sometimes for a very urgent diagnosis and histochemistry. </li></ul>
    50. 63. Renal Infarction
    51. 64. Liver cirrohsis
    52. 65. Liver carcinoma
    53. 66. <ul><li>3.Electron Microscopic Investigation </li></ul><ul><li>study disorders at an organelle level and subcellular details. </li></ul><ul><li>transmission and scanning EM </li></ul>
    54. 69. <ul><li>4.Histochemical and Immunohistochemical Investigation </li></ul><ul><li>Histochemistry is the study of the chemistry of tissues after treated with specific reagents, so that the chemical features of individual cells can be visualised. </li></ul>
    55. 70. Normal glomerulus
    56. 71. Membranous GN
    57. 72. A masson trichrome preparation shows complete replacement of virtually all glomeruli by blue-staining collagen. Chronic glomerulonephritis:
    58. 73. <ul><li>Immunohistochemistry </li></ul><ul><li>Ag-Ab complexes </li></ul><ul><li>The bound Ab is then visualized, using another Ab and a dye complex such as diaminobenzidine. </li></ul>
    59. 78. Section D about the subject of Pathology, How to learn pathology?
    60. 79. Pathology <ul><li>“ Is the foundation of medical science and practice. Without pathology, the practice of medicine would be reduced to myths and folklore” </li></ul>
    61. 80. Pathology The Status of Pathology in Medicine a bridging discipline the clinical practice of medicine basic science
    62. 81. Learning Pathology: <ul><li>General Pathology </li></ul><ul><ul><li>Common changes in all tissues. </li></ul></ul><ul><ul><ul><li>E.g.. Inflammation, cancer, ageing. </li></ul></ul></ul><ul><li>Systemic Pathology </li></ul><ul><ul><li>Specific changes in organs. </li></ul></ul><ul><ul><ul><li>E.g.. Goiter, pneumonia, breast cancer. </li></ul></ul></ul>
    63. 82. <ul><li>General pathology is concerned with the basic reactions of cells and tissues to abnormal stimuli that underlie all diseases. </li></ul><ul><li>Systemic pathology examines the specific </li></ul><ul><li>responses of specialized organs and </li></ul><ul><li>tissues to more or less well defined stimuli. </li></ul>
    64. 83. Subdivisions of Pathology: <ul><li>Histopathology </li></ul><ul><li>Cytopathology </li></ul><ul><li>Haematology </li></ul><ul><li>Microbiology </li></ul><ul><li>Immunology </li></ul><ul><li>Chemical Pathology </li></ul><ul><li>Genetics </li></ul><ul><li>Toxicology </li></ul><ul><li>Forensic Pathology </li></ul><ul><li>Histopathologist </li></ul><ul><li>Cytologist </li></ul><ul><li>Haematologist </li></ul><ul><li>Microbiologist </li></ul><ul><li>Biochemist </li></ul><ul><li>Geneticist </li></ul><ul><li>Toxicologist </li></ul><ul><li>Forensic Pathologist </li></ul><ul><li>Molecular Biologist </li></ul>
    65. 84. <ul><li>Chinese proverb </li></ul><ul><li>I hear, I forget; </li></ul><ul><li>I see, I remember; </li></ul><ul><li>I do, I understand. </li></ul>
    66. 85. Past and Present….! <ul><li>In the past, .. people mistook magic for medicine…! </li></ul><ul><li>Now people mistake medicine for magic….! </li></ul>