“A sebaceous cyst is a small lump or bump on the skin which is non-cancerous. It is most frequently found on the face, scalp, neck, upper chest and upper back. However, cysts can occur anywhere else on the skin.” Dr Ganesh, MBBS, MMED, G&L Specialist Doctor and Resident Expert explains.
“A sebaceous cyst is usually diagnosed by a doctor in a physical examination of your skin. Sometimes, your doctor will perform a biopsy to rule out other skin growths.” This means a tissue sample of your skin is taken and sent to the laboratory for detailed examination.
In the case of a 77-year-old Caucasian man presented with a sebaceous (epidermoid) cyst on his scalp in 2019, he shared that he has had the cyst for many years and it always seemed to remain the same. He was concerned because recently, its size had increased significantly. Based on the cyst’s rapid growth and his clinical history of malignancies, clinicians determined that the mass should be excised and sent to pathology for examination, where it was discovered to be malignant.
Thankfully, after some consideration, the patient decides to go ahead with complete excision of the tumour. The patient recovered well without any significant complications or additional adjunctive chemotherapy or radiation treatments, and the incisions heal nicely.
While it is rare for a sebaceous or epidermoid cyst to present malignancies, our doctor may recommend surgically removing highly suspicious lesions. Also, they should be scrutinised to identify any risk of developing cancer.
As with the case above, Dr Ganesh of G&L Surgical recommends a physical examination of your skin to determine the state of the sebaceous cyst. “It is often difficult to determine the condition of the patient’s cyst without conducting a close examination. Typically, suppose I noticed signs of discolouration or rapid growth. In that case, I will advise the patient to have the cyst removed and perform an excision biopsy to identify if they could potentially be malignant.
What Causes a Sebaceous Cyst?
Our sebaceous glands produce oil, called sebum, that coats your hair and skin. A sebaceous cyst forms out of these sebaceous glands. Cysts may develop if the gland or duct becomes compromised or damaged. This typically occurs due to trauma to the area. Trauma may refer to a scratch, skin conditions such as acne, or a surgical wound. Since sebaceous cysts grow slowly, the trauma could have occurred weeks or months before the formation of the cyst.
A sebaceous cyst may also be caused by a deformed duct or damage to the cells caused by surgery Genetic conditions (Gardner’s syndrome or basal cell nevus syndrome). As sebaceous cysts can develop on any part of the skin, cases have presented that they can develop even on areas least expected, such as the hand.
A 35 yr old female presented with swelling over the knuckle region of the right hand developing for three months. On examination a soft cystic swelling by the doctors overseeing her case. As the swelling was seemingly getting more extensive, the region of the sebaceous cyst was immediately excised and treated.
When Can You Tell if Your Sebaceous Cyst is Unusual?
A sebaceous cyst is a common non-cancerous cyst of the skin. While most people with sebaceous cysts can go about their life normally, there are certain red flags to look for when it comes to determining if your sebaceous cyst requires more medical attention.
A sebaceous cyst is considered unusual, and potentially cancerous, if it has the following characteristics:
- A diameter that is larger than five centimetres
- A fast rate of recurrence after removal
- Signs of infection including redness, pain, or pus drainage
As with the case of a 63-year-old male teacher with immunosuppression from steroid treatment. He developed a painful sebaceous cyst on his upper back. After suffering from his sebaceous cyst for two weeks, he finally sought medical advice, and by then the gauze-covered wound had self-erupted and was leaking a foul-smelling fluid.
Immediate treatment was given where the wound was irrigated with normal saline, within a month of treatment, his infected sebaceous cysts went from a size of 4cm to 0.5cm upon recovery.
Why Should You Surgically Remove a Sebaceous Cyst?
A sebaceous cyst does not usually disappear by itself, and it is best to remove the cyst before it grows larger or gets infected. Surgery is a practical and safe method of removing cysts. In some instances, sebaceous cysts may become cancerous. Surgery to remove the cyst, plus a biopsy is recommended. This is called an excision biopsy.
Other complications may arise from the cyst such as infection, pain and discomfort. Should a cyst be infected or inflamed, this can result in a lot of discomfort. The inflammation is usually treated before the cyst can be removed. Sebaceous cysts are typically removed from the face for cosmetic reasons.
For more information on how sebaceous cysts are treated, head over to our surgeries page.