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Epidermal Inclusion Cyst - Causes, Symptoms, Complications, Diagnosis, and Treatment

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Epidermal Inclusion Cyst - Causes, Symptoms, Complications, Diagnosis, and Treatment

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An epidermal inclusion cyst is a type of cutaneous cyst. It is a benign cyst and rarely transforms into malignant. Read this article to know more.

Written by

Dr. Ramji. R. K

Medically reviewed by

Dr. Kartikay Aggarwal

Published At August 2, 2022
Reviewed AtMay 22, 2024


A cyst is a pathological cavity filled with fluid, semifluid, or gaseous contents not created by the accumulation of pus. Most of the cysts are lined by epithelium, but not all are. Cysts lined by epithelium are known as “true cysts,” whereas cysts not lined by epithelium are known as “pseudocysts.” An epidermal inclusion cyst is a type of cutaneous cyst, and it is the most common of all types of cutaneous cysts.

The other names by which epidermal inclusion cysts are denoted are:

  • Epidermoid cyst.

  • Epidermal cyst.

  • Infundibular cyst.

  • Keratin cyst.

Epidermal inclusion cysts are sometimes referred to as sebaceous cysts; however, this is a misnomer as they do not involve any sebaceous gland. Epidermal inclusion cysts are mostly benign (non-cancerous). However, in a rare scenario, they may transform into malignancies. Malignant cases account for just about one percent of the cases.

What Does Epidermal Inclusion Cyst Look Like?

As it is a cutaneous cyst, an epidermal inclusion cyst is seen beneath the skin. Their characteristic appearance is dome-shaped lumps, which are slowly enlarging, painless, mobile, and fluctuant, often seen along with a punctum (a minute point from which surrounding tissues differ in color and appearance). Epidermal inclusion cyst deep inside the skin communicates with the outer skin through a keratin-filled orifice. Through this orifice, a malodorous yellowish cheese-like material is discharged. Their size may range from a few millimeters to centimeters. Its contents include degraded keratin and lipid materials.

Where Does Epidermal Inclusion Cyst Occur?

Epidermal inclusion cysts are the most common cutaneous cysts. They occur most commonly in the face, neck, scalp, back, chest, arms, legs, and genitalia and originate from the follicular infundibulum (upper portion of the follicle).

What Are the Epidermal Inclusion Cysts Filled With?

The epidermal inclusion cyst will be filled with keratin and cell debris. When these substances are draining, they look thick, yellow, and have a foul odor.

What Causes Epidermal Inclusion Cysts?

Epidermal inclusion cysts occur mostly randomly. They do not have any genetic linkage; however, certain genetic conditions are associated with the development of epidermoid inclusion cysts.

These include:

  • Gardner syndrome (a type of familial adenomatous polyposis).

  • Gorlin syndrome (an inherited disorder that affects many organs and tissues of the body).

  • Favre-Racouchot syndrome (a disorder that consists of open and closed comedones in actinically damaged skin).

Chronically damaged skin due to sunlight exposure in old people is more likely to develop epidermal inclusion cysts, and certain medications are associated with this development.

That includes,

  • BRAF inhibitors.

  • Imiquimod.

  • Cyclosporine.

Epidermoid inclusion cysts originate from the follicular infundibulum, and any disruption to the follicular infundibulum may result in cyst development. They can also occur due to the implantation of the epithelium into the skin below by any penetrating injury or trauma.

Who Is Most Commonly Affected by the Epidermal Inclusion Cyst?

They most commonly occur in the third and fourth decades of life. Male predilection is seen as compared to females (ratio 2:1). They are rarely seen before puberty.

What Are the Symptoms of Epidermal Inclusion Cyst?

The symptoms include a dome-shaped lump that is mobile, fluctuant, and painless. Sometimes, the lump may become painful as it gets infected and inflamed. The skin becomes red over the affected area. The condition is usually benign but may rarely transform into a malignant one.

How to Diagnose Epidermal Inclusion Cyst?

A simple clinical examination could provide a valuable diagnosis. In certain cases, your doctor might suggest other tests to rule out other findings.

These include,

  • Punch Biopsy: The pathologist examines a small amount of tissue removed from the affected area. This helps rule out any cancer associated with the cysts and gives a definitive diagnosis of the condition.

  • Ultrasound: Ultrasound helps determine the cystic contents. They appear as a round, oval-shaped, and well-circumscribed mass in the subcutaneous tissue.

  • Computed Tomography (CT) Scan: A CT scan gives a detailed view of the cyst and helps the surgeon plan for treatment for cyst removal.

  • MRI (Magnetic Resonance Imaging): MRI is very useful in delineating whether the cyst is benign or malignant.

How Is Epidermal Inclusion Cyst Treated?

In most cases, epidermal inclusion is left untreated as the condition is harmless and painless. The inflamed and uninfected cysts resolve spontaneously without treatment. However, closely monitoring the condition is necessary, as the cyst may rarely become painful and inflamed. It does not always transform into a malignant condition. Some of the different ways to treat the inflamed, painful conditions include:

  • To reduce swelling, a doctor might suggest injecting a steroid medication into the affected area.

  • Incision and drainage are done to drain out the yellowish, cheesy material discharging through the cyst via the skin orifice. Drainage of cysts avoids the chance of further infection in the affected area.

  • Surgical excision helps remove the cyst completely. Your doctor will give local anesthesia to numb the affected area surrounding the cyst before the procedure.

What Are the Complications Seen in Epidermal Inclusion Cyst?

Some of the potential complications seen in epidermal inclusion cysts are,

  • Inflammation: The cyst may appear swollen and tender even without cyst infection. Your doctor will suggest some anti-inflammatory medication before surgical removal of the cyst.

  • Rupture of Cyst: Rupture of the cyst often leads to infection.

  • Infection: An infection in the affected area leads to a severely painful condition. Doctors suggest antibiotics to treat the infection and subside the pain.

  • Skin Cancer: Rarely, the epidermal inclusion cyst may transform into cancer. A cyst with such malignant potential requires complete removal to prevent its recurrence.

Is Epidermal Inclusion Cyst Contagious in Nature?

No, epidermal inclusion cysts are not contagious.

Some common risk factors are

  • The person is past puberty.

  • If the person is affected by a rare inherited condition, such as Gardner syndrome,.

  • Injury to the skin.

Is an Epidermoid Cyst a Sign of Cancer?

This condition is rarely harmful; some have seen these cysts become malignant.

  • Squamous cell carcinoma.

  • Basal cell carcinoma.

These cysts can be concerning if

  • They show signs of infection, such as pain, swelling, and skin discoloration.

  • Quick growth.

  • Size is more than five centimeters.


Epidermal inclusion cysts are the most common cutaneous cysts. They are mostly benign and rarely transform into malignant. Once infected, the cyst becomes painful. A doctor might suggest treatments like surgery, incision and drainage, and medication to treat the cyst. Although this condition occurs spontaneously, certain preventive measures, like avoiding trauma and injury to the skin and chronic sun exposure, could reduce the risk of developing the condition.

Frequently Asked Questions


How Is an Epidermal Inclusion Cyst Treated?

The most common form of treatment for epidermal inclusion cysts is surgical excision, in which the cyst and sac are entirely removed. A small incision, drainage of the contents, and removal of the cyst wall are some minor excision approaches that may be employed in certain circumstances. Antibiotics are another kind of treatment for infected cysts, as does observation in the case of asymptomatic cysts.


Is It Possible for an Inclusion Cyst to Become a Cancer?

Cysts with epidermal inclusions are generally benign and unrelated to malignancy. Rarely, though, a persistent, untreated cyst may have problems like infection, inflammation, or unusual changes like squamous cell carcinoma. If the cyst's size, appearance, or symptoms change, it is essential to watch them and seek medical advice for the best diagnosis and treatment options.


How Harmful Are Epidermal Cysts?

Generally speaking, benign epidermal cysts are not hazardous. However, they could be uncomfortable, contagious, or an aesthetic issue. To deal with any symptoms or side effects brought on by epidermal cysts, a medical professional's proper evaluation, and treatment are advised.


Is It Necessary to Remove an Epidermoid Cyst?

An epidermoid cyst typically doesn't need to be removed until it exhibits symptoms, becomes infectious, or raises aesthetic issues. However, a medical practitioner might advise removal if the cyst is uncomfortable, causing recurring infections, or if the diagnosis is unclear.


How Is a Cyst Naturally Treated?

Cysts can often be treated. However, these methods often focus on symptom management and recovery. These can include using warm compresses to ease pain and encourage drainage, practicing good hygiene, and refraining from popping or squeezing the cyst to prevent infection. However, it's crucial to seek the advice of an expert in medicine for a precise diagnosis and direction on available natural therapy alternatives.


How Long Does Epidermal Cyst Recovery Take?

Depending on the complexity and size of the cyst, the surgical approach employed, and personal healing capacities, the recovery period following an epidermal cyst removal often lasts a few days to a few weeks. For optimum healing, adhering to the postoperative care instructions and attending any prescribed follow-up appointment is crucial.


Does a Cyst Require Surgery to Be Removed?

Not all cysts can be removed surgically. Smaller, asymptomatic cysts may not require treatment or may be handled without surgery. However, surgical intervention is frequently necessary for the total excision of bigger, symptomatic, or recurrent cysts.


When Do Epidermoid Cysts Develop?

Keratin, a protein present in the epidermis, gets trapped beneath the skin's surface to form epidermoid cysts. Trauma, clogged hair follicles, or a congenital disease can all cause this. The cysts frequently develop gradually over time and may be seen as tiny, rounded bumps under the skin.


Is Removing an Epidermal Cyst Painful?

An epidermal cyst is often removed while the patient is under local anesthetic, which helps to numb the area and lessen pain. The cyst is removed or drained during the procedure, and the tissue around it is sutured. There can be some discomfort while you're recovering discomfort or mild pain, but it can be handled with painkillers and appropriate wound care.


Is Surgery to Remove Cysts Safe?

Cyst removal surgery is generally risk-free when done by a trained medical expert. Although they are uncommon, complications can include infection, hemorrhage, scarring, or the cyst returning. To guarantee complete healing and reduce risks, it's critical to adhere to post-operative instructions, maintain the surgery site clean, and show up for any required follow-up appointments.


Do Epidermoid Cysts Classify as Tumors?

Tumor classification does not often apply to epidermoid cysts. They are benign, non-cancerous, resulting from entrapped skin cells rapped. On the other hand, tumors are aberrant, unchecked cell growths that might be benign or malignant. Instead of becoming cancers, epidermoid cysts are categorized as benign cystic lesions.


What Cyst Size Requires Surgery?

The size of a cyst is not the only factor considered when deciding whether to operate on it. Considerations are made based on symptoms, location, appearance, and probable problems. Cysts greater than 5 cm in diameter or seriously bothering a patient's quality of life and capacity for daily activities or appearance may be candidates for surgical removal. A healthcare expert should, however, make the final choice following a careful review.


Which Surgery Is Best for Cyst Removal?

The size, location, and kind of cyst all influence the optimal surgery for cyst removal. Excision, in which the cyst is completely removed, and drainage, in which the cyst is perforated and its contents are drained, are two common surgical procedures. A healthcare practitioner decides the precise surgical strategy depending on the patient's unique situation and the desired result.
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Dr. Kartikay Aggarwal
Dr. Kartikay Aggarwal



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