L3.7.3: Skin Cancer

• • Most common form of cancer in humans
  • Most important risk factor is overexposure to ultraviolet (UV) radiation in sunlight and tanning beds
  • CLASSIFICATION OF CANCER
  • Benign
  • Malignant


  Skin cancer
• neoplasm (tumor) has not spread

  Benign
• the neoplasm has invaded other body areas

  Malignant
• Common types of cancer

  • Basal Cell Carcinoma
  • Squamous Cell Carcinoma
  • Malignant Melanoma
• • Least malignant
  • Most common type of skin cancer
  • Arises from cells in stratum basale that are altered so that they can no longer make keratin
  • Lesions appear as shiny, dome-shaped nodules that develop a central ulcer


  Basal Cell Carcinoma
• • Believed to be induced by UV exposure
  • Arises from cells of stratum spinosum
  • Lesions appear as scaly, reddened papules that gradually form shallow ulcers
  • Early removal allows a good chance of cure
  • Metastasizes to lymph nodes if not removed


  Squamous Cell Carcinoma
• • Most deadly of skin cancers, but accounts for only 5% of skin cancers
  • Arises from melanocytes
  • Metastasizes rapidly to lymph and blood vessels
  • RECOGNIZING MELANOMA:
  • A - ASYMMETRY: Two sides of pigmented mole do not match
  • B - BORDER IRREGULARITY: Borders of mole are not smooth
  • C - COLOR: Different colors in pigmented area
  • D - DIAMETER: Spot is larger than 6mm in diameter
  • E - EVOLUTION: One or more of the ABCD characteristics are evolving


  Malignant Melanoma