Introduction to Pathology: The Study of Disease by Dr. Amitabha Basu, MD

1. Introduction to pathology Dr. Amitabha Basu MD

2. What is Pathology ? It is the study (logos) of the sufferings (pathos).

3. It’s a laboratory

4. Basic Sciences P T H O L O G Y Clinical Medicine

5. Various Divisions of pathology • Clinical Pathology • Molecular Pathology • Hematopathology • Histopathology • Cytopathology • Blood banking

7. Clinical Pathology Automatic Analyzer

8. Clinical pathology • A branch of pathology concerned with patient care.

9. Molecular Pathology

10. Molecular Pathology • A branch of pathology concerned with the study of the diseases and mechanisms of disease on a molecular or chemical level.

11. Human immunodeficiency virus, viral particles at medium magnification adjacent to cell surface, electron micrograph.

12. Hematopathology

13. Hematopathology • This branch deal with the Disease of the Blood. This peripheral blood smear is stained with the Wright's stain. (Leishman stain)

14. Here is a laboratory instrument called a Coulter Counter

15. CBC (complete blood count) : from Coulter blood cell counter

16. Cytopathology: Study of cellular change in the diseased tissue.

17. Cytopathology Study of cell Tissue composed of many cell of similar function

18. Two methods to obtain the cells • Exfoliative cytology ( collect and examine the cell that falls –off from the tissue) • FNAC (Fine needle Aspiration Cytology): cell obtained with a fine needle.

19. What is that mean ? • Exfoliated cells ( eg from Cervix) for quick diagnosis of malignancy • Stain Uses: • Papanicolaou Stain Pap Smear

21. If there is malignancy- it will look like this

22. Cervical Cytology • It helps in early diagnosis of cancer of Uterine Cervix. So, you can prevent a cancer like this!!

23. FNAC [ fine needle aspiration cytology ] Cells obtained from an abnormal mass in the body : EG Breast lump

24. Pathologist performing an FNAC from thyroid and breast

25. Aspirated Thyroid cells shows features of malignancy : Aspirated cells stained with Giemsa Stain It is quick. Less expensive No hospital stay required

26. Histopathology Study of tissue Tissue composed of many cell of similar function

27. Histopathology- a technique to identify a disease by looking at the tissue! House of final diagnosis. • Tissue is collected and fixed with formalin- overnight- it takes time!. • It is then embedded in paraffin and cut with microtome- 3 micron thick. • This thin tissue is then stained with Hematoxiline & eosin( H&E) stain. • Following that it is mounted with DPX and cover slip.

28. Normal Squamous cell and Histopathology of Squamous cell carcinoma. Definition of histopathology: Pathological Study of the minute structure, composition, and function of diseased tissues.

29. Histopathology An important procedure to rule out or confirm malignancy. Stain Used : Hematoxylin and Eosin Stain [ H & E ]

30. Biopsy • The removal and examination of a sample of tissue from a living body for diagnostic purposes

32. Biopsy sample then sent to the Histopathology laboratory Tissue were kept in the Formalin for Fixation and to avoid autolysis

33. Frozen section • Paraffin section takes time--- • If you need a quick section…..we harden the tissue by freezing it…frozen section.

34. Frozen Sections • It is necessary to get a rapid diagnosis of a pathologic process. • The piece's are snap frozen in a cold liquid or cold environment (-20 to -70 Celsius). • Freezing makes the tissue solid enough to section with a microtome.

35. Cutting a frozen section. Cryostat.

36. Use of frozen section technique. • To check to presence of tumor in surgical resected ends, while removing a tumor from the body. • To check for the presence of metastasis tumor in lymph node. • To identify fat.

37. This is not enough! So we need special stains!

38. Special steins and common Use

39. Special steins and common Use

40. Blood Bank

41. Blood Bank • Optimal Blood Testing, Preservation and Utilization of Blood and blood products.

42. Donate Blood to save a life

43. Welcome once again to the world of Pathology Why ? How ? Where ? = Answer this and you will get your diagnosis

44. How to study pathology ? Easy • Learn • Whyis the disease = Etiology • What are the types = Classification • How the disease occur = Pathogenesis • Where = Morphological Change of the organ effected • What happens then = Clinical significance. Follow this pattern and you will never forget pathology

45. Understanding of a few terms: and also study pathology in this sequence. • Etiology • Pathogenesis • Morphology • Gross change of a diseased organ/tissue • Microscopical change of the tissue and cells. • Functional Derangement and Clinical Significance

46. Etiology • Cause of the disease. • Example : Chronic Alcoholism is the etiology of fatty liver.

47. Pathogenesis Definition : Mechanism of disease formation • Alcohol produce injury to the liver cells , following that Liver cells (Hepatocytes) become unable to metabolize Fatty acid. • And it accumulate in the liver cells to produce fatty liver.

48. Pathogenesis : narrowing of the coronary artery : Myocardial Infarction.

49. Gross visible change of a diseased organ/tissue. Microscopical change of the tissue and cells. Morphology : 2 parts

50. Morphology: Gross change in the diseased organ.