local invasion
Last reviewed 01/2018
Benign tumours do not infiltrate or invade surrounding tissue. However, the effect of the increased local volume of cells often places pressure on surrounding tissues. This commonly results in compression and atrophy of the latter giving a pseudo-capsule that permits easier removal of the discrete tumour during surgery. Local expansion uncommonly gives rise to complications because of the effects of compression of nearby structures, e.g. nerves and vessels.
Malignant tumours are characterised by the ability to infiltrate and invade. Often this occurs in a haphazard manner without a clear limit of advancement and no capsule to make easier surgical resection. In this case, it is necessary to remove the visible edge of abnormal tissue with a margin of normal tissue, e.g. lymphatics, dependent on the tumour type and degree of aggressiveness - radical surgery.