Prelim

• Pathology is the study of diseases, also known as pathobiology
• It involves the study of the structural & functional changes in cells, tissues, and organs that underlie diseases
• According to Rudolf Virchow, all diseases originate at a cellular level
• Diseases and underlying mechanisms are best understood in the context of normal cellular structure and function
• Pathology involves the examination of surgically removed organs and tissues for biopsy samples
• There are two branches of pathology: Autopsy and Biopsy
• Autopsy involves the systematic examination of a cadaver to determine the cause of death
• Autopsy uses methodical procedures to determine the etiology and pathogenesis of disease
• Purposes of autopsy include family counsel, determining the cause of death, epidemiological purposes, genetic causes, and understanding pathogenesis of diseases
• Biopsy involves the examination of cells or tissues from a living organism
• Biopsy is when Excised material may be studied to diagnose disease or confirm normal findings
• Incisions can be total or partial, with partial lesions removed in the form of "wedges" or "cylindrical" shapes
• Aspects of diseases forming the core of pathology include etiology (cause), pathogenesis (mechanism of development), morphological changes (structural alterations), and clinical significance (functional consequences)
• A Pathologist is a physician who specializes in interpreting and diagnosing changes caused by diseases in the body
• Pathologists are experts in determining the origin and development of diseases and analyzing body tissues microscopically
• Pathologists study all aspects of diseases with a focus on nature, causes, and development of abnormal conditions, as well as structural and functional changes resulting from disease processes
• Medical Laboratory Scientists or Medical Technologists perform diagnostic analysis of human blood, urine, and other body fluids
• There are two types of pathology: General and Systemic
• General pathology studies basic reactions of cells and tissues to abnormal stimuli underlying all diseases
• Systemic pathology studies specific responses of specialized organs and tissues to well-defined stimuli
• Focuses on specific changes in organs, such as goiter for the thyroid gland, pneumonia for lungs, and breast cancer
• There are three divisions of pathology: Gross Pathology, Anatomic Pathology, and Clinical Pathology
• Gross Pathology involves the macroscopic examination of surgical specimens for disease recognition
• Example: Brain slices undergoing gross pathology
• Anatomic Pathology studies changes in function, structure, or appearance of organs or tissues, including postmortem examinations and biopsy specimens
• Includes branches like Surgical Pathology, Autopsy Pathology, and Exfoliative Cytology
• Clinical Pathology is directed towards the diagnosis and monitoring of diseases through examination of blood, body fluids, and tissue biopsy specimens
• Identifies and interprets changes characterizing different diseases or disease states in cells, tissues, and body fluids
• Sections under Clinical Pathology/Laboratory include Blood Banking, Clinical Chemistry, Clinical Immunology & Serology, Hematology, and Microbiology
• Clinical Chemistry involves biochemical analysis on human samples outside the body, including toxicology
• • Punch Biopsy: done with a circular blade attached to a pencil-like handle, primary technique for obtaining diagnostic whole thickness skin specimens
  • Shave Biopsy: done with a small scalpel or curved razor blade
  • Curettage Biopsy: done on the surface of tumors or small epidermal lesions with minimal to no topical anesthetic using a round curette blade
• Biopsy:

  • Removal of cells or tissues for examination from a living subject to determine the presence or extent of a disease
  • Types of Biopsies:
  • Excisional Biopsy: entire lump or suspicious area is removed
  • Incisional or Core Biopsy: sample of tissue is removed with preservation of histological architecture
  • Fine Needle Aspiration Biopsy (FNAB): sample of tissue or fluid is removed using a needle, simplest & least invasive type
  • Other types of Biopsies:
• Methods of instrumentation include fluorometry, spectrophotometry, enzyme kinetic, electrophoresis, and mass spectrometry
• Toxicology analyzes blood, urine, and body fluids for drugs or substances of abuse
• Hematology assesses cellular elements in blood samples, involving enumeration of blood cells and microscopic observation of stained peripheral blood smears
• Hematopathologists specialize in hematology, examining bone marrow and lymph node biopsies
• Necrosy/Autopsy:

  • Postmortem Examination or Autopsia Cadaverum
  • After death examination of the body and dissection of internal organs to confirm or determine the cause of death
  • Can uncover existence of diseases not detected during life or determine extent of injuries contributing to death
  • Preliminaries for PME (Postmortem Examination):
  • Written consent required from next of kin in a specific order
  • Death certificate usually in colored form (blue)
  • Medical abstract or clinical data required
  • Medicolegal clearance needed
• • PME permitted without consent in specific circumstances
• Blood Banking deals with the collection, storage, compatibility, and safety of blood and its components for human transfusion
• Microbiology isolates, cultures, and identifies microorganisms in biological samples, including parasites, fungi, bacteria, and viruses