Dermoid Cyst vs Epidermoid Cyst

Dermoid and epidermoid cysts are two of the most common types of skin cysts found in both children and adults. They often appear as small, slow-growing lumps under the skin. Most remain harmless for many years and rarely cause pain in the early stages. The confusion begins when both look similar on the surface. A clear understanding of benign cyst differences helps patients know when to seek treatment and what to expect during diagnosis.

Dermoid and epidermoid cysts come from ectodermal tissue, the same layer that forms the skin, hair and nails. They are benign, but they may press on nearby structures if they grow in sensitive areas like the spine, face or neck. This guide explains their symptoms, diagnosis and treatment based on current medical knowledge.

What Are Dermoid and Epidermoid Cysts?

A cyst is a hollow sac that contains skin material. Both dermoid and epidermoid cysts are lined with skin cells. These cells shed naturally. The shed material collects inside the cyst and causes the cyst to grow slowly over time.

• An epidermoid cyst is lined by simple skin cells. It contains keratin, oil and dead skin cells.
• A dermoid cyst contains more complex elements such as hair follicles, hair strands, sweat glands, sebaceous glands and sometimes additional structures like cartilage or tooth-like material.

Both remain non-cancerous in most cases. They do not spread to other parts of the body.

Key Differences of Dermoid and Epidermoid Cysts at a Glance

The table below summarises the major distinctions.

Feature	Dermoid Cyst	Epidermoid Cyst
Contents	Keratin, hair follicles, hair, sweat glands, sebaceous glands	Keratinised epithelial cells
Origin	Trapped ectoderm with skin appendages	Trapped ectoderm with simple squamous epithelium
Histology	Complex with multiple skin structures	Simple lining with squamous epithelium
Imaging Findings	Often shows fat; usually T1-hyperintense on MRI	Usually resembles CSF; isointense on T1 and T2
Common Locations	Head, neck, midline body structures	Face, trunk, off-midline areas
Growth Pattern	Slow but may enlarge due to glandular activity	Slow, based on keratin build-up
Treatment	Surgical excision	Surgical excision; drainage not recommended

Similarities Between Dermoid and Epidermoid Cysts

Despite their differences, both cyst types share key features:

• Both are usually congenital, although epidermoid cysts may also appear later in life.
• Both grow slowly as they collect skin material.
• Both appear as firm, painless lumps under the skin.
• Both remain benign but can rarely undergo malignant transformation.
• Both require surgical removal if they cause symptoms or keep growing.

These similarities often make visual diagnosis difficult.

What Are the Key Cyst Symptoms and Causes?

Most cysts start small. They may stay unnoticed for years. Symptoms begin when the cyst enlarges or presses on a nearby structure.

Common Symptoms

• A firm lump under the skin
• Gradual increase in size
• Redness if the cyst becomes inflamed
• Mild discomfort or pressure
• Drainage of thick material from the cyst (more common in epidermoid cysts)

Symptoms depend on the location. Dermoid and epidermoid cysts inside the spine may cause:

• Weakness in the limbs
• Clumsiness
• Trouble walking
• Numbness or tingling
• Loss of bladder or bowel control

Symptoms appear because the cyst compresses the spinal cord or spinal nerves.

Causes

The most common causes of dermoid and epidermoid cysts can be categorized into two classes: 

Congenital

• These cysts form early during embryonic development.
• They result from trapped ectodermal cells.
• Dermoid cysts often contain skin structures because of this early developmental stage.

Acquired

• These occur later due to skin cells entering deeper tissues after an injury or procedure.
• Epidermoid cysts may appear after trauma or repeated irritation.
• Some may arise after surgical procedures like a lumbar puncture.

Also Read: Fibroid vs Cyst

How Are Dermoid and Epidermoid Cysts Diagnosed?

A cyst is usually first identified during a physical exam. Imaging confirms the type and complexity.

Ultrasound

An ultrasound scan helps confirm that the lump is a cyst. It shows the size, consistency and internal echoes.

MRI

MRI provides the most detailed information. Dermoid cysts often contain fat, which appears bright on T1-weighted images. Epidermoid cysts often resemble cerebrospinal fluid.

MRI helps doctors see:

• The exact location
• The relationship to nearby structures
• The presence of fat, oil or keratin
• Whether the cyst has ruptured

CT Scan

CT is useful for cysts in the skull, spine or face. It helps identify bone changes caused by long-term pressure.

Biopsy

A biopsy confirms the diagnosis. The cyst wall and contents show clear differences under the microscope.

Which Factors Increase the Risk of Dermoid and Epidermoid Cysts?

Dermoid and epidermoid cysts are rare. They are seen more often in children and young adults. Risk depends on origin.

Congenital Risk

Cysts may form during early development. Conditions associated with congenital cysts include:

• Spinal dysraphism
• Dermal sinus tract
• Spina bifida
• Myelomeningocele

Dermoid cysts are more common in congenital cases.

Iatrogenic Risk

These cysts may form after a medical procedure. Epidermoid cysts may appear after:

• Repeat needle procedures
• Lumbar puncture
• Surgical closure of spinal abnormalities

Accidental implantation of skin cells causes the cyst to grow.

When to Remove Cysts?

Most cysts grow slowly. Many cause no symptoms for years. Surgical removal becomes important when the cyst causes any of the following: 

• Grows steadily
• Causes pain or pressure
• Limits movement
• Becomes infected
• Compresses nerves or the spinal cord
• Causes cosmetic concerns
• There is uncertainty about the diagnosis

Cysts in the spine almost always require removal because of the risk of nerve damage.

How are Epidermoid and Dermoid Cysts Treated?

Treatment for epidermoid and dermoid cysts depends on where the cyst is located, how fast it grows and the symptoms it creates. Here’s what you can expect for the treatment: 

Dermoid Cyst Treatment

Dermoid cysts are treated with complete surgical removal. The goal is to remove the entire cyst, including its wall. A dermoid cyst may contain hair, glands and fatty tissue, so careful removal is important.

Microsurgical Removal

Dermoid cysts inside the spine or deeper tissues are removed using microsurgery. The procedure may involve:

• General anesthesia
• A laminectomy is required to reach the spinal canal if the cyst is inside the spine
• Exposure of the cyst under a surgical microscope
• Careful separation of the cyst from nerves
• Removal of the cyst contents
• Removal of the cyst wall as safely as possible

If the cyst wall is firmly attached to the spinal cord or nerves, complete removal may not be safe. The surgeon removes the portion that can be taken out without causing harm.

Recovery

Recovery depends on the size and location of the cyst. Most patients return to regular activity after healing. Dermoid cysts that are completely removed have a very low chance of returning.

Epidermoid Cyst Treatment

Epidermoid cysts are simpler and lined with squamous epithelial cells. These cysts contain keratin and dead skin material. Complete removal prevents recurrence.

Microsurgical Removal

Surgical excision is the preferred epidermoid cyst treatment. The steps often include:

• General anesthesia for deep or spinal cysts
• A laminectomy if the cyst is located inside the spine
• Exposure of the cyst with a surgical microscope
• Gentle separation from nearby nerves
• Removal of the cyst’s keratin-filled sac
• Removal of the cyst lining to reduce recurrence

If the wall adheres strongly to the spinal cord or spinal nerves, the surgeon removes what can be taken out safely.

Recovery

Epidermoid cysts usually heal well after surgery. Patients resume daily activities once the incision heals. The risk of recurrence is low when the lining is removed completely.

Visit Apollo Spectra for Expert Cyst Care!

Dermoid and epidermoid cysts remain benign, but they may cause symptoms when they grow or press on nearby structures. You now have a clear understanding of how they differ, how they are diagnosed and when treatment becomes necessary. If you want guidance for dermoid cyst diagnosis, treatment for epidermoid cyst or support for any cyst-related concern, specialists at Apollo Spectra can help you at every step. They will offer a personalized plan based on your symptoms, imaging results and overall health. 

Do not wait for the cyst to grow or disturb your routine. Book your appointment with our experts today and feel confident knowing that your care is handled with clarity, safety and precision!