Pathology

Pathology services refer to a wide range of diagnostic tests and procedures used to understand diseases, diagnose conditions, monitor disease progression, and guide treatment. Pathology primarily involves examining body fluids, tissues, and cells to identify abnormalities that indicate disease or health conditions. These services are provided by pathologists, medical professionals who specialize in studying the causes and effects of diseases.

 

1. Clinical Pathology

Clinical pathology involves the analysis of bodily fluids (such as blood, urine, and saliva) to diagnose disease and monitor treatment. It is divided into several subfields:

A. Hematology

  • Hematology tests focus on blood-related diseases, including anemia, leukemia, and clotting disorders.
  • Common tests include:
    • Complete Blood Count (CBC): Measures the levels of different types of blood cells (red blood cells, white blood cells, and platelets).
    • Blood Smear: Examines the appearance of blood cells under a microscope.
    • Coagulation Tests: Measure the blood’s ability to clot (e.g., PT, aPTT).
    • Bone Marrow Biopsy: Assesses bone marrow function, especially in cases of blood cancers like leukemia.

B. Clinical Chemistry

  • Clinical chemistry involves testing blood and urine for chemical components, such as enzymes, hormones, electrolytes, and metabolites.
  • Common tests include:
    • Liver Function Tests (LFTs): Measures enzymes and proteins in the blood to evaluate liver health.
    • Kidney Function Tests: Measures substances like creatinine and urea to assess kidney function.
    • Lipids and Lipoproteins: Tests cholesterol and other fats in the blood to assess heart disease risk.
    • Electrolyte Panel: Measures sodium, potassium, calcium, and other ions in the blood.

C. Microbiology

  • Microbiology services involve the study and identification of pathogens like bacteria, viruses, fungi, and parasites.
  • Common tests include:
    • Blood Cultures: Detect infections in the bloodstream.
    • Urine Cultures: Identify urinary tract infections (UTIs).
    • Throat and Nasal Swabs: Used to detect infections like strep throat or respiratory viruses.
    • Stool Cultures: Identify gastrointestinal infections caused by bacteria, viruses, or parasites.

D. Immunology and Serology

  • Immunology deals with the immune system, studying how the body defends itself against infections and diseases.
  • Serology tests for the presence of antibodies or antigens in the blood, often used to detect infections or autoimmune diseases.
  • Common tests include:
    • HIV Test: Detects the presence of HIV antibodies or antigens.
    • Rheumatoid Factor: Detects rheumatoid arthritis or other autoimmune conditions.
    • Liver Panel: Used to diagnose liver diseases like hepatitis.
    • Allergy Tests: Identify sensitivities to allergens (e.g., pollen, food, dust).

2. Anatomical Pathology

Anatomical pathology involves the study of tissues, cells, and organs to diagnose disease through examination of physical specimens. This is critical for the diagnosis of cancers, infections, and many other conditions.

A. Histopathology

  • Histopathology examines tissue samples (biopsies) under a microscope to identify disease, inflammation, or abnormal tissue changes.
  • Common procedures include:
    • Biopsy: A sample of tissue is taken from the body (e.g., from the liver, lungs, or skin) and examined for signs of disease.
    • Frozen Section: A rapid biopsy procedure used during surgery to determine if tissue is cancerous.
    • Tissue Staining: Special stains are applied to tissues to highlight specific cell types or abnormalities.

B. Cytopathology

  • Cytopathology involves the examination of individual cells from body fluids, smears, or biopsies to detect cancer or other diseases.
  • Common tests include:
    • Pap Smear: A screening test for cervical cancer by examining cells from the cervix.
    • Fine Needle Aspiration (FNA): A minimally invasive technique to collect cells from lumps or masses (e.g., thyroid or breast).
    • Sputum Cytology: Examining mucus from the lungs for signs of cancer or infection.

C. Autopsy Pathology

  • Autopsy involves post-mortem examination to determine the cause of death and to study the effects of diseases.
  • Autopsies can be clinical (to understand disease progression) or forensic (to investigate the cause of suspicious deaths).

3. Molecular Pathology

Molecular pathology integrates molecular biology with pathology to identify genetic changes associated with diseases like cancer, genetic disorders, and infectious diseases.

  • Common applications include:
    • Genetic Testing: Identifying genetic mutations associated with inherited conditions (e.g., cystic fibrosis, sickle cell anemia).
    • Cancer Genetics: Detecting specific mutations in tumor DNA (e.g., BRCA1/BRCA2 mutations for breast cancer risk).
    • Polymerase Chain Reaction (PCR): Used to detect specific genetic material, such as viral RNA in cases of HIV or COVID-19.
    • Next-Generation Sequencing (NGS): A high-throughput method used to analyze large numbers of genes or entire genomes to understand complex diseases.

4. Blood Transfusion Services

Blood transfusion pathology involves testing and screening donated blood and matching it with recipients to ensure compatibility and prevent reactions. It includes:

  • Blood Typing: Determining the ABO blood group and Rh factor.
  • Crossmatch: Ensuring the compatibility between donor and recipient blood before a transfusion.
  • Screening for Infections: Checking donated blood for infections like HIV, Hepatitis B/C, and syphilis.

5. Toxicology

Toxicology tests identify the presence of harmful substances in the body, such as drugs, alcohol, and poisons. These tests are essential in:

  • Overdose Management: Identifying substances in cases of suspected overdose.
  • Drug Monitoring: Checking for therapeutic levels of drugs (e.g., blood thinners, anti-seizure medications).
  • Workplace Drug Testing: Detecting drug use in employees as part of safety or legal compliance.

Importance of Pathology Services

  1. Accurate Diagnosis: Pathology is key to diagnosing a wide range of diseases, from infections to cancers, and helps guide medical treatment.
  2. Monitoring Disease Progression: Pathology tests help monitor how a disease is progressing, whether it’s improving with treatment or worsening.
  3. Personalized Treatment: Molecular and genetic testing can guide personalized treatment plans, especially in cancer care, to identify targeted therapies.
  4. Preventative Healthcare: Pathology plays a critical role in screening for diseases (e.g., cancer, genetic disorders) before symptoms arise, allowing for early intervention.