Generally, they are benign painless lumps under the skin, but have the potential to become painful and/or infected. This is best avoided by their removal under local anesthesia.

What is a sebaceous cyst?

A skin cyst is a fluid-filled lump just underneath the skin. A cyst usually is a slow-growing lump that can move easily under the skin. These cysts are closed sacs that can be found under the skin of the entire body (except the palms of the hands and soles of the feet). They affect young and middle-aged adults, and are particularly common in people with acne.

What are the causes sebaceous cysts?

Some of the cells in the top layer of skin produce keratin, a protein that gives skin its strength and flexibility. Normally, these cells move up to the surface of the skin as they start to die so they can be shed. But the cells sometimes move deeper into your skin and multiply, forming a sac. They secrete keratin into the middle of the sac, which forms a thick, yellow paste. Sebaceous cysts may be caused by blocked glands or swollen hair follicles in the skin.

Hence, Sebaceous cysts form out of your sebaceous gland. Cysts develop if the gland or its duct (the passage from which the oil is able to leave) becomes damaged or blocked. This usually occurs due to trauma to the area.

The trauma may be a scratch, a surgical wound, or a skin condition, such as acne. Sebaceous cysts grow slowly, so the trauma may have occurred weeks or months before you notice the cyst.

Other causes of a sebaceous cyst may be :

• malshaped or deformed ducts
• damage to the skin during surgery
• genetic/Familial conditions

What are the symptoms of sebaceous cysts?

Small cysts are typically not painful. Large cysts can range from uncomfortable to considerably painful. Large cysts on the face and neck may cause pressure and pain.

This type of cyst is typically filled with white flakes of keratin, which is also a key element that makes up your skin and nails. Most cysts are soft to the touch.

Areas on the body where cysts are usually found include:

• scalp
• face
• neck
• back
• Genital Area

Typically, the feeling of the lump is unpleasant. In some cases, however, cysts can get inflamed and become painful and tender to the touch. The skin on the area of the cyst may be red and warm. Drainage from the cyst appears greyish-white and cheese-like, and has a foul smell.

A sebaceous cyst may be considered atypical — and possibly cancerous — if it has the following characteristics:

• a diameter that’s larger than 5 centimeters
• a fast rate of reccurrence after being removed
• signs of infection, such as redness, pain, or pus draining out.

Diagnosis Of Sebaceous Cyst :

A sebaceous cyst is often diagnosed after a simple physical examination. If your cyst is atypical, it may require additional tests to rule out possible cancer. You may also need these tests if you wish to have the cyst surgically removed.

Common tests used for a sebaceous cyst include:

• MRI scan, which helps spot atypical characteristics and find the best route for surgery
• Ultrasound scan which identifies the contents of the cyst
• punch biopsy, which involves removal of a small amount of tissue from the cyst for histological diagnosis.