A trichilemmal cyst, also known as a pilar cyst, is a growth that forms in a hair follicle, causing it to swell with fluid. These growths usually are benign, but a doctor might recommend removal if they cause pain or distress, because they are sometimes unpleasant to look at and are tender to the touch. Removal can take place in a clinic on an outpatient basis, and it does not take very long, especially if the dermatologist is skilled.
Trichilemmal cysts form thickened walls and swell over time beneath the surface of the skin. They can appear anywhere on the body and are especially common around the head and neck. A dermatologist can conduct a quick examination to determine the nature of the growth and might recommend removal. Sometimes the trichilemmal cyst is mistaken for a malignancy, in which case the doctor might request a biopsy to check on the cyst's contents.
To remove a trichilemmal cyst, the dermatologist typically administers a local anesthetic for the patient's comfort and excises the whole cyst. Some might drain the growth first and then pull out the shell of the cyst. The doctor might request a biopsy for safety if he or she has concerns about malignancy. Patients often need anti-inflammatory drugs after the procedure to address swelling and any residual inflammation left behind by the cyst.
In about 2 percent of cases, a trichilemmal cyst can turn malignant. These growths might include a proliferation of cells that can spread to neighboring tissues. For this reason, doctors often recommend removal even if a cyst doesn't appear to be a problem, to prevent the development of a cancerous growth. A patient who has a history of trichilemmal cysts should make sure to bring this up if he or she goes to the doctor to discuss a skin problem, because this could provide an important diagnostic clue.
Some families appear to have a genetic predisposition to trichilemmal cyst formation. Members of such families might want to stay alert to the early signs of cyst formation so they can get prompt treatment. It also can help to note the family history in patient charts to make doctors aware of the increased risk of cysts for a patient. This can be helpful when the doctor examines a patient who has a growth that appears ambiguous in nature; if the patient's family often develops trichilemmal cysts, the doctor might logically assume that this is the most likely explanation for the growth.