8.2.10 Two Types of Tumours

1. Benign Tumours

• Growth Rate: Slow-growing.
• Spread:
  • Localised: Do not invade other tissues or spread to distant parts of the body.
  • Non-invasive.
• Effects on Body:
  • Usually cause limited harm, but can lead to mechanical damage by pressing on blood vessels, nerves, or surrounding tissues.
• Characteristics:
  • Encapsulated (often enclosed in a fibrous capsule).
  • Cells retain normal structure and differentiation.
• Treatment:
  • Easier to remove surgically.
  • Rarely recur after removal.

2. Malignant Tumours

• Growth Rate: Fast-growing.
• Spread:
  • Invasive: Invade nearby tissues, damaging their structure and function.
  • Metastasis: Spread to distant parts of the body through the bloodstream or lymphatic system, forming secondary tumours.
• Effects on Body:
  • Severe impact: Disrupts vital processes in the body.
  • Can lead to life-threatening complications.
• Characteristics:
  • Lack a defined structure and are unencapsulated.
  • Cells are poorly differentiated and show abnormal structure.
• Treatment:
  • Difficult to treat; requires aggressive measures such as chemotherapy, radiotherapy, or surgery.
  • High risk of recurrence and spreading.

Key Differences Between Benign and Malignant Tumours

Feature	Benign Tumours	Malignant Tumours
Growth Rate	Slow	Rapid
Spread	Localised; no metastasis	Spread via metastasis to other areas
Effect on Body	Limited harm; mechanical pressure	Severe harm; disrupts vital processes
Treatment	Easier to treat; low recurrence	Harder to treat; high recurrence risk
Cell Structure	Normal; well-differentiated cells	Abnormal; poorly differentiated cells