Infiltration (medical) - Classification

Classification

As part of a disease process, infiltration is sometimes used to define the invasion of cancer cells into the underlying matrix or the blood vessels. Similarly the term may describe the deposition of amyloid protein. During leukocyte extravasation white blood cells move in response to cytokine chemicals (chemotaxis), from within the blood out to infiltrate into the diseased or infected tissues. The presence of lymphocytes in tissue in greater than normal numbers is likewise called infiltration.

As part of medical intervention, local anaesthetics may be injected at more than one point so as to infiltrate an area prior to a surgical procedure. However the term may also apply to unintended iatrogenic leakage of fluids from phlebotomy or intravenous drug delivery procedures, a process also known as extravasation or "tissuing".