A sebaceous cyst is a typically harmless protein-filled yellow or white lump that can move easily under the surface of the skin. Sebaceous cysts typically grow slowly and take on a dome-like shape beneath the skin. There are several hundred different types of cysts. Epidermoid cysts, for example, originate directly from the skin. Pilar cysts, on the other hand, originate from hair follicles. While epidermal cysts are sometimes confused for sebaceous cysts, epidermal cysts do not involve the sebaceous gland and contain dead skin cells.
True sebaceous cysts originate from the sebaceous glands and can be located anywhere on the body with the exception of the palms of the hands and the soles of the feet. The areas of the body containing the greatest amount of sebaceous glands per square centimeter include the genitals, back, chin, and forehead. Most sebaceous glands connect directly to hair follicles, but some others exist on the open surface of the skin. Sebaceous glands produce a mixture of lipids known as sebum, which makes up part of the oils found on the surface of the skin. These lipids include glycerides, wax esters, free fatty acids, squalene, and cholesterol.
A sebaceous gland has a lifespan of roughly one week, after which it disintegrates and subsequently produces sebum, an oily, waxy substance that helps to protect the skin from damage. Sebum has many functions, including reducing water loss from the surface of the skin and protecting the skin from infection and excess bacteria. In addition, sebum is colonized by a bacteria known as propionibacterium. Some physicians and researchers believe that propionibacterium may play a role in regulating immune system functions.
Symptoms of Sebaceous Cysts
The primary symptom of a sebaceous cyst is a small lump under the skin that is typically painless. In some cases, the lump can become tender to the touch and result in redness and inflammation. Some sebaceous cysts will go away on their own while others require treatment and sometimes surgical excision to be completely removed.
Causes of Sebaceous Cysts
Sebaceous cysts can develop when the sebaceous gland or its duct becomes damaged or blocked. Traumas to the sebaceous gland such as a scratch, a surgical wound, certain skin conditions, or genetic predispositions can lead to blockages of the sebaceous gland or duct, resulting in a sebaceous cyst. These cysts can also form due to a misshapen or deformed sebaceous duct.
Sebaceous Cyst Diagnosis
The diagnosis of a sebaceous cyst is normally confirmed after the cyst has been removed from the body. In some instances, a biopsy may be performed to rule out the possibility of diagnosing other skin growths or types of cysts. If the cyst is suspected to be abnormal or potentially cancerous, an ultrasound, biopsy, or CT scan can determine the nature of the mass. A fast rate of cyst growth after initial removal as well as a cyst having a diameter of five centimeters or more can indicate that a sebaceous cyst is potentially cancerous.
Prevention of Sebaceous Cysts
While sebaceous cysts should be kept clean to avoid re-infection, most sebaceous cysts are not preventable because they typically originate from trauma to the sebaceous gland. Sebaceous cysts should never be picked, rubbed, or squeezed.
Sebaceous Cyst Treatment
As long as the cyst is not growing in size and is not bothersome to the patient, they present little danger to the patient outside of mild discomfort. Large cysts, while uncomfortable, are often innocuous. If a cyst becomes inflamed, however, there are several methods to remove a sebaceous cyst. A steroid may first be injected into the cyst to reduce swelling and inflammation. Furthermore, a medical professional can drain the cyst that is infected or particularly large or bothersome.
There are several methods to have the cyst removed from the skin. The most simple method of extraction is to make a small incision on the skin to remove the cyst and associated hair follicle. Some methods of surgically removing the cyst include laser-aided excision, minimal excision, and punch excision in which the cyst and a portion of the surrounding skin are removed using a scalper resembling a cookie cutter. It is important to note that attempting to burst and drain the cyst without a medical professional can lead to an infected cyst. Going against medical advice and excising a cyst without the guidance of a medical professional can lead to poor or inadequate wound healing, unsatisfactory cosmetic outcomes, and a higher risk of cyst recurrence.
After initial diagnosis or treatment, RS Surgical offers surgical excision for symptomatic cysts that are not acutely infected. This procedure can be performed in our office with local anesthesia and minimal discomfort. After the cyst has been removed, an antibiotic ointment may be prescribed to prevent infection. A scar cream may also be used to reduce the appearance of any surgical scars. Recovery from this process usually takes between one and two weeks depending on the size and nature of the cyst.