Infiltration (medical)

Types of Infiltration

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

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

Main article: Pulmonary infiltrate

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

References

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3. (October 1993). "Topical Review Article: Brainstem and Other Malignant Gliomas: II. Possible Mechanisms of Brain Infiltration by Tumor Cells". Journal of Child Neurology.
4. (2022-06-23). "Diagnosing the cause of pulmonary infiltrates in an acutely unwell patient". BMJ Case Reports.
5. (December 2022). "Macrophages in Lupus Nephritis: Exploring a potential new therapeutic avenue". Autoimmunity Reviews.
6. (2019-10-28). "Ultrasound-based techniques for the diagnosis of liver steatosis". World Journal of Gastroenterology.
7. (2024-09-12). "Fatty infiltration of extraocular muscles on magnetic resonance imaging". Orbit.
8. (October 2022). "Fatty infiltration in the intact supraspinatus tendon; a normal physiological response with increasing age and female gender". Shoulder & Elbow.
9. Meechan, John G.. (September 2011). "The use of the mandibular infiltration anesthetic technique in adults". The Journal of the American Dental Association.