The term 'infiltration' is frequently used to describe various pathologic and physiologic processes, including but not limited to:
Immune Infiltration This occurs when immune cells like
lymphocytes and
macrophages migrate into tissues in response to infection, injury, or inflammation, aiding in defense and healing but potentially contributing to
autoimmune diseases if misdirected. Immune cells (especially lymphocytes) also infiltrate into malignant tumors and other neoplasms.
Malignant Infiltration infiltrating
bone marrow, an example of malignant infiltration Malignant infiltration involves
cancerous cells invading surrounding healthy tissues by breaching normal cellular boundaries, which allows tumors to grow locally and facilitates
metastasis to distant organs. This is especially relevant for cancers that cross the
blood-brain barrier and cause secondary
brain tumors.
Pulmonary Infiltration This term refers to the accumulation of substances such as fluids, immune cells, bacteria, proteins, foreign particulate matter, and other things within the lung tissue, often detected as non-distinct infiltrates on imaging studies.
Tissue biopsy and other tests are frequently used to determine the nature of pulmonary infiltrates, as there are many possible causes.
Immune Complex Infiltration Antibody-antigen immune complexes can sometimes
precipitate out of
serum and infiltrate tissues surrounding
capillaries and other small blood vessels. Pathologically, this is often relevant in lung disease and
kidney disease. These typically interact with local
complement proteins or induce other immune system responses, resulting in a
Type III hypersensitivity reaction.
Fatty Infiltration Also known as
steatosis, where excessive fat accumulates within cells of organs like the
liver or
muscle fibers. It is often linked to
hyperlipidemia, among other risk factors.
Anesthetic Infiltration A medical technique involving the injection of
local anesthetics into tissues to provide numbness for minor surgical procedures or pain relief. ==References==