BIOL282

• What dermatological conditions are diagnosed using punch biopsies?

  • Rashes
  • Inflammatory skin conditions (e.g., lupus, psoriasis)
  • Suspicious lesions for melanoma or non-melanoma skin cancer
• Why is the concentration of fixative optimized?

  To achieve the best balance between fixation rate, cost, and quality
• What are the uses and characteristics of Fine Needle Aspiration (FNA) needle biopsies?

  Uses:

  • Designed for extracting cellular samples from superficial masses (e.g., skin, subcutaneous nodules)
  • Used for extracting cellular samples from deeper tissues (e.g., lymph nodes, thyroid, breast)

  
  

  Characteristics:

  • Minimally invasive and quick
  • Does not retain tissue architecture
  • Commonly used for initial diagnostic evaluations, especially in oncology
• What is the mechanism of acid decalcifiers?

  They react with calcium in tissue to form salts
• How do histopathology and cytopathology differ in their methods and diagnostic applications?

  Histopathology:

  • Processes entire tissue sections
  • Involves fixing, embedding, sectioning, and staining.
  • Visualizes tissue architecture and cellular relationships.
  • Uses stains like haematoxylin and eosin (H&E).

  
  

  Cytopathology:

  • Examines individual cells from fluids, smears, or aspirates.
  • Identifies cellular abnormalities without full tissue architecture.
  • Uses stains like Papanicolaou or Romanowsky.
• What is cytopathology?

  The microscopic examination of individual cells to diagnose disease
• What is often added to commercial formalin formulations to stabilize them?

  Methanol
• How is formalin solution buffered to prevent artifacts?

  To maintain neutral pH
• What is atrophy and what are some types of atrophy?

  Atrophy is reduced cell size or number causing organ shrinkage; types include disuse, neurogenic, hormonal effects, ischemic, pressure, brown, senile, and generalised atrophy
• What are the different forms of healing?

  1. Regeneration: Restores original tissue structure by replacing damaged cells with identical ones.
  2. Repair (Scar Formation): Deposition of collagen by fibroblasts to form a scar where regeneration is insufficient.
  3. Recovery: No tissue loss, minor damage, and tissue returns to normal.