Difference Between Benign & Malignant Tumours

When a living cell in the body loses its control over the normal cell division due to some external or internal factors, it starts multiplying at a much faster rate, loosing all restraints and controls. This purposeless proliferation of cells usually forms a mass known as Tumour or Neoplasm, which may be benign or malignant in character. The benign tumour is usually encapsulated and grows in size at one site. It remains within the tissue of its origin and does not spread to other parts of the body. The benign tumour can be completely removed by surgery. On the other hand, malignant tumour invades adjoining tissues and also spreads to distant tissues and organs of the body through various routes including lymphatic and vascular channels. The concept of dividing tumours into benign and malignant groups is too rigid. It has been observed that there is a third group of the tumours, which can invade locally but do not metastasise. These tumours are called intermediate tumours, which include: adenoma of the bronchus, mixed salivary tumour, carcinoid tumour and basal cell carcinoma. Some of the benign tumours can become malignant. Some or all of the following changes may be observed when a benign tumour turns malignant: rapid growth of the tumour; increased vascularity of the tumour; fixation of the tumour; and metastasis of the tumour.