Sebaceous Cyst

What are sebaceous cysts?

Sebaceous cysts are slightly hardened, fluid-filled bumps within the skin, which are considered to be noncancerous.  The size of a sebaceous cyst ranges from pea-sized, at about one centimeter across to around five centimeters across.

A cyst generally is a slow-growing lump that can move easily under the skin.  Sebaceous cysts are found under the skin. Palms of the hands and soles of the feet are the usual areas where a sebaceous cyst may be found.  

Blocked glands, trauma, as well as swollen hair follicles,  are some of the causes of a sebaceous cyst.  

Cysts sometimes are also inherited. Generally, a sebaceous cyst grows very slowly and does not cause pain.  However, the sebaceous cyst can become inflamed or infected, with the overlying skin becoming red, tender, and sore.  Sebaceous cysts occur on a site that is constantly irritated. When the cyst gets infected, it drains out a cheesy, bad-smelling material and can look bad cosmetically.

What do these cysts usually contain?

Sebaceous cysts are generally mobile masses that consist of:

• Fibrous tissues and fluids.
• A fatty (keratinous) substance that resembles cottage cheese and due to this the cyst may be called keratin cyst.  This material has a cheesy appearance to it as well as emits a foul odor.
• It may sometime contain serosanguineous fluid.  A serosanguineous fluid generally contains purulent and bloody material.

Causes of sebaceous cyst

Some of the causes of sebaceous cyst include:

• Blocked sebaceous gland:  The sebaceous gland produces the oil called sebum that coats the hair and skin.  Cysts can develop if the gland or its duct from which the oil is able to leave becomes damaged or blocked.
• Swollen hair follicle:  A swollen hair follicle or folliculitis is a skin condition in which hair follicles become inflamed.  Bacterial or fungal infections are the main culprits of folliculitis.  At first, it looks like small red bumps or white-headed pimples around hair follicles, which are the tiny pockets from which hair grows.
• High levels of testosterone:  Testosterone is the most important androgen in the human body.  Androgens encourage sebum production. Therefore, due to higher androgen levels, seborrheic glands produce more sebum, which is an oily substance leading to coarse pores of the skin.  Consequently, acne and acneiform eruptions are more common in seborrheic areas such as the face, upper thorax, back, and shoulders.  Due to androgen, there is abnormal thickening of the outer layer of the skin and the sebum is trapped within the follicle and this, in turn, leads to acne lesions and also cause cysts.
• Use of androgenic anabolic steroids:  High dosages of anabolic-androgenic steroids increase skin surface lipids, and these lipids cover the outer layer of the skin and cause Propionibacteria acne and sebaceous cysts.
• Hereditary causes:  Gardner syndrome is a medical condition where GI polyps, multiple osteomas, and skin and soft tissue tumors are formed.  The skin symptoms associated with Gardner syndrome include epidermoid cysts, desmoid tumors, and other benign tumors.  Basal cell nevus syndrome is a combination of health defects, which is caused by a rare genetic condition. This condition affects the skin, endocrine system, nervous system, eyes, and bones.

What are the symptoms?

Small sebaceous cysts are typically not painful.  Large sebaceous cysts can be uncomfortable and considerably painful.  Large cysts on the face and neck may even cause pressure and pain. A sebaceous cyst is typically filled with white flakes of keratin, which is also a key element that constitutes the skin and nails.  Most sebaceous cysts are soft to the touch and are considered noncancerous. Common areas on the body where cysts are usually found include:

• • Scalp.

• • Face.

• • Neck.

• Back.

A sebaceous cyst can be possibly cancerous if it has the following characteristics:

• • The diameter of the cyst is larger than five centimeters.

• • Immediate recurrence in a very short span of time after being removed.

• If the cyst tends to appear infected with signs and symptoms correlating to redness, pain, or pus drainage.

How is it diagnosed?

Diagnosis of a sebaceous cyst is made when a doctor conducts a simple physical examination.  If the sebaceous cyst is unusual in appearance, the doctor may order additional tests to rule out possible cancers and a person may also need these tests if he or she wishes to have the cyst surgically removed.

Common tests used for a sebaceous cyst include CT scans, which can determine the root cause of the cyst and aid in surgery.  Ultrasounds may also be performed to determine the contents of the cyst. Lastly, a punch biopsy may be required to test the tissue from the cyst to determine if the cyst is cancerous.

How is a sebaceous cyst treated?

Treating a sebaceous cyst will require a consult from a medical professional to assess the sebaceous cyst and determine if needs to be left alone or to be managed medically either by medication therapy or through surgery if found to be malignant.

Generally, sebaceous cyst needs to be left alone and they cause little harm to the daily lifestyle. Any action such as picking, rubbing, or squeezing the cyst may cause damage and lead to infection of the cyst. When the cyst gets infected, it is likely to cause pain and discomfort as well as worsen its appearance.  

Consulting a doctor is the best option to deal with skin cysts that are causing concern or producing symptoms. The doctor can treat a cyst by draining it or by surgically removing it. Since most cysts are not harmful to the health, a doctor will allow the patient to choose the treatment option that suits the patient.  

It is important to note that without surgical removal, a cyst will usually return back and the best treatment is by removing the cyst completely from the root through surgery.

When a cyst is decided to be removed by surgery, the doctor may use one of the following methods to remove the sebaceous cyst.

• • Traditional wide excision.  This method involves complete excision of the cyst, but since it involves a wide opening to perform the surgery, the patient may end up with a long scar.

• • Minimally invasive excision.  This method involves minimal excision of the cyst with a minimal amount of opening but carries a risk of recurrence of the cyst.

• Laser incision followed by punch biopsy excision.  This method is a more sophisticated process of removing the cyst, which involves the laser to make a small hole to drain the cyst of its contents and the outer walls of the cyst is physically removed during a secondary procedure.

Reasons why it should be removed

There are several reasons that can contribute to the doctor to decide on removing the cyst through surgery.  The main reason leading to this decision may be because the cyst may be causing problems, which may be because of infection, if the cyst alters a person lifestyle, or if it is found in a prominent location.  

The sebaceous cyst may be removed a the doctor’s office and generally involves a consent from the patient, sterilizing the area to avoid spreading of the infection to other parts of the body using a drape and sterile kit, local anesthetic to numb the area, and a blade and other instruments to cut the cyst out.  The doctor may prefer to lance the cyst if the cyst is already draining due to the infection.

Doctors removing a cyst will mainly aim to remove the cyst completely since any leftover part of the cyst may cause the cyst to return at a later stage. A microincision technique involves emptying the cyst sac with the chemical phenol.  In other cases, there are many cases that a person may have a cyst and not have any symptoms or discomfort associated with it.

Steps for safe sebaceous cyst removal

• • A sebaceous cyst that is inflamed needs to be left alone and not be incised until the inflammation subsides.  Generally, inflammation settles over 4 weeks. Antibiotics may be required to subside the inflammation. Cephalexin or Cloxacillin is the first choice of antibiotics provided.

• • Incision and drainage of the sebaceous cyst is recommended only when the cyst becomes swollen due to the fluid build up.

• • Lidocaine with epinephrine can be used for hemostasis to reduce the bleeding during the incision and drainage process.  It is advisable to not inject anesthetics on the cyst to avoid rupture of the cyst. Sufficient time needs to be provided for the anesthetic take effect and monitor the pressure of the cyst by palpating.

• • Choosing the appropriate skin incision makes it much easier for the cyst to be excised.  A linear incision is advised if the cyst is not inflamed or scarred whereas a radical incision is preferred for a recurrent cyst.

• • The initial incision performed with the scalpel should be mild and not be incised applying pressure in order to avoid incising completely through the cyst.  A curved hemostat is used as the instrument of choice until visualizing the cyst.

• • Blunt dissection is a preferred method rather than a scalpel to dissect around the cyst whereas the solid areas of connective tissue can be divided with a scalpel.

• • Hemostats should be placed immediately if the cyst gets ruptured and use the scalpel to complete the process in a faster way and avoid sebum contact with the wound.

• • Small and moderate sized cysts can be closed with a vertical mattress technique whereas small incisions can be closed using interrupted stitches.  Absorbable Vicryl or Monocryl stitches can be placed for large wounds.

• Clean wounds thoroughly and send the patient home with dressings that will not allow blood to leak through.

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