Skin lesion aspiration is the withdrawal of fluid from a skin lesion (sore).
A needle is inserted into the skin sore or skin abscess, which may contain fluid or pus. Fluid from the sore or abscess is withdrawn. The fluid may be examined under a microscope. A sample of the fluid may also be sent to a lab. There, it is put in a lab dish (called a culture medium) and watched for growth of bacteria, virus or fungi.
You do not need to prepare for this test.
The health care provider may inject a numbing medicine (anesthetic) into the skin before inserting the needle if the sore is deep.
How the Test will Feel
You may feel a pricking sensation as the needle enters the skin.
In many cases, removing the fluid will lessen pressure within the skin sore and ease pain.
Why the Test Is Performed
This test is used to find the cause of a fluid-filled skin lesion. It can be used to diagnose skin infections or cancers.
What Abnormal Results Mean
Abnormal results may be a sign of infection caused by bacteria, fungi, or viruses. Cancer cells may also be seen.
There is a small risk of bleeding, mild pain, or infection.
Chernecky CC, Berger BJ. Biopsy, site-specific - specimen. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:199-202.
Ruocco E, Baroni A, Donnarumma G, Ruocco V. Diagnostic procedures in dermatology. Clin Dermatol. 2011;29(5):548-556. PMID: 21855731 www.ncbi.nlm.nih.gov/pubmed/21855731.