Epidermoid Cysts: Symptoms, Types, Causes and Treatment

Epidermoid cysts, sometimes referred to as epidermal inclusion cysts, are common benign lesions that can appear in a wide range of body locations—from the skin to deeper tissues such as the brain and spinal cord. While they are generally slow-growing and not life-threatening, their symptoms, underlying causes, types, and treatment options can vary greatly depending on their location and any associated complications. Understanding these aspects is essential for accurate diagnosis, effective management, and optimal patient outcomes.

Symptoms of Epidermoid Cysts

Epidermoid cysts often present subtly, but their symptoms can become troublesome, depending on their size, location, and whether complications such as infection or rupture occur. Recognizing the full spectrum of symptoms is vital for early intervention and management.

Symptom	Commonality	Notable Locations	Sources
Lump/Mass	Very common	Scalp, skin, skull, oral	6 10 18
Pain	Occasional	Spine, skin	3 10 19
Headache	Frequent	Intracranial, skull	1 2 4
Neurological	Variable	Brain, spinal cord	1 2 3 7 8
Infection	Rare	Skin, skull, scrotum	9 14
Cosmetic Issue	Common	Head, neck, face	10 18

Table 1: Key Symptoms

Common Presentations

The most typical symptom is a palpable, slowly enlarging lump beneath the skin, often on the scalp, face, neck, or trunk. This lump is usually painless unless it becomes inflamed or infected. In many cases, an epidermal punctum (a small, central opening) may be visible on the surface of the cyst, serving as a hallmark for diagnosis 10 18.

Neurological Symptoms

When epidermoid cysts occur in the brain or spinal cord, symptoms are more diverse and location-dependent:

• Intracranial Cysts: Headaches, seizures, cranial nerve palsies (such as facial weakness, hearing loss, or visual disturbances), vertigo, and ataxia are prominent. These symptoms often result from the cyst compressing adjacent neural structures 1 2 7.
• Spinal Cysts: Pain, motor and sensory deficits, and sphincter dysfunction may occur, especially if the cyst is compressing nerve roots or the spinal cord itself 3 8 19.

Infections and Complications

Although rare, epidermoid cysts can become infected, causing pain, redness, and swelling. In cases involving the skull, complications such as otitis media (middle ear infection) have been reported due to the cyst eroding into nearby structures 9 14.

Cosmetic and Functional Concerns

For cysts located on visible areas such as the face or scalp, cosmetic issues are common reasons for seeking medical attention. On rare occasions, cysts can interfere with function—such as swallowing or breathing if located intra-orally 5 10 18.

Types of Epidermoid Cysts

Epidermoid cysts are not a single entity; their behavior and impact can vary widely based on their anatomical location and etiology. Recognizing the different types helps tailor the diagnostic and therapeutic approach.

Type	Location(s)	Notable Features	Sources
Cutaneous	Skin, scalp, face	Benign, visible lump	10 18
Intracranial	Brain, skull	Neurological symptoms	1 2 4 7
Intraspinal	Spinal cord, lumbar	Pain, deficits	3 8 11 19
Intradiploic	Skull bone (calvarium)	Lump, bone erosion	4 6 9
Oral/Head-Neck	Sublingual, submandib.	Dysphagia, dyspnea	5 10
Genital (Scrotal)	Scrotum, penis	Rare, slow-growing	13 14

Table 2: Types of Epidermoid Cysts

Cutaneous Epidermoid Cysts

These are the most familiar type, presenting as firm, round nodules beneath the skin. They most often occur on the scalp, face, neck, and trunk, but can appear anywhere, including unusual sites like the palms, soles, or genital skin 10 18.

Intracranial Epidermoid Cysts

Though rare (<1% of all brain tumors), these cysts most commonly occur in the cerebellopontine angle and other basal cisterns. Symptoms usually emerge in adulthood and reflect slow, progressive compression of neural structures 1 2 7 15.

Intraspinal Epidermoid Cysts

Found within or adjacent to the spinal cord, these cysts can be congenital or acquired (sometimes due to previous lumbar puncture or trauma). They most often cause pain, neurological deficits, or sphincter dysfunction, depending on their location 3 8 11 19.

Intradiploic Epidermoid Cysts

Occurring within the bones of the skull, these cysts can erode bone and sometimes extend into the brain or adjacent structures. They often present as painless lumps but may cause neurological symptoms if they enlarge 4 6 9.

Oral and Head-Neck Cysts

These rare cysts develop in the oral cavity, particularly in sublingual and submandibular regions, and can mimic other masses. Large lesions may cause swallowing or breathing difficulties 5 10.

Genital Epidermoid Cysts

Occasionally, these cysts form on the scrotum or penis. Their origin may be linked to trauma, infection (e.g., HPV), or other factors. They are generally benign but can become inflamed or, rarely, undergo malignant transformation 13 14.

Causes of Epidermoid Cysts

Understanding what leads to the formation of epidermoid cysts requires exploring both congenital and acquired mechanisms, as well as unique triggers in specific anatomical sites.

Cause	Mechanism	Sites Affected	Sources
Congenital	Ectodermal inclusion during dev.	Brain, spine, skull	1 3 8 14
Trauma	Implantation of epidermal cells	Skin, spine, palms	10 11 12
Iatrogenic	Post-medical procedures	Spine (post-lumbar)	11
Infection (HPV)	Viral-induced cyst formation	Palms, anogenital	12 13 14
Genetic Syndromes	Hereditary predisposition	Multiple cysts	18

Table 3: Causes of Epidermoid Cysts

Congenital Origin

Many epidermoid cysts, especially those in the brain, skull, and spinal cord, are congenital. They arise from the inclusion of ectodermal tissue during embryonic development, particularly as the neural tube closes. These inclusions gradually form cysts over decades, often presenting in adulthood 1 3 8 14.

Trauma and Implantation

Traumatic implantation of epidermal elements into the dermis is a well-recognized cause, especially in areas prone to injury or surgical intervention. This is common in cutaneous cysts and, notably, in intraspinal cysts following repeated lumbar punctures 10 11.

Iatrogenic Causes

Medical interventions—most notably lumbar punctures—can inadvertently implant epidermal tissue into deeper structures, leading to cyst formation years later. This is particularly relevant in the spine 11.

Infection (HPV and Others)

Certain cysts, especially those on the palms, soles, and genitalia, have been linked to human papillomavirus (HPV) infection. These cysts may be caused by viral-induced proliferation of epidermal cells, as evidenced by the detection of HPV DNA in some lesions 12 13 14.

Genetic and Syndromic Associations

Rarely, multiple epidermoid cysts are a feature of genetic syndromes such as Gardner syndrome and Lowe syndrome, which increase the predisposition to develop these cysts throughout the body 18.

Treatment of Epidermoid Cysts

Appropriate management of epidermoid cysts is essential to prevent recurrence, manage symptoms, and address cosmetic or functional concerns. Treatment strategies are tailored to the cyst’s location, size, and presence of complications.

Approach	Indication	Key Points	Sources
Surgical Excision	Symptomatic, large, or risky	Complete removal preferred	1 3 15 18
Laser Therapy	Cosmetic concern, facial cysts	Minimal scarring	17
Observation	Small, asymptomatic cysts	Monitor for changes	14 18
Medical Therapy	Inflamed/infected cysts	Antibiotics, steroids	14 7

Table 4: Treatment Options for Epidermoid Cysts

Surgical Excision

Surgical removal is the treatment of choice for most epidermoid cysts, especially those that are symptomatic, growing, or in high-risk locations (e.g., brain, spinal cord). Complete excision of the cyst wall is crucial to prevent recurrence. For intracranial and spinal cysts, microsurgical techniques are employed to balance maximal removal with preservation of neurological function. In some cases, the cyst capsule may be left behind if it is firmly adherent to vital structures, accepting a small risk of recurrence 1 3 15 18 19.

• Cutaneous cysts: Usually excised under local anesthesia with low complication rates 18.
• Intracranial/spinal cysts: Require specialized neurosurgical approaches. Postoperative complications, such as aseptic meningitis or hydrocephalus, may occur, but mortality is rare 1 2 15.

Laser Therapy

For patients particularly concerned about scarring or in cases where cysts are in cosmetically sensitive areas, erbium:YAG laser fenestration is an emerging alternative. This technique decompresses the cyst with minimal invasiveness and excellent cosmetic outcomes, though recurrence risk may be higher than with complete excision 17.

Observation

Small, asymptomatic cysts can often be safely observed, especially if they are not causing discomfort or functional problems. Regular follow-up is advised to monitor for growth, inflammation, or signs of malignancy 14 18.

Medical Management

In cases of infection or inflammation, initial management with antibiotics or corticosteroids is appropriate. For inflamed cysts, surgery is typically delayed until the infection has resolved. In rare cases of malignant transformation, additional oncologic management may be needed 7 14.

Conclusion

Epidermoid cysts are a diverse group of benign lesions that can arise in almost any part of the body. Their symptoms, types, causes, and treatments vary significantly depending on their location and underlying etiology. Effective management requires a nuanced understanding of these factors to tailor the approach to each individual patient.

Key Takeaways:

• Symptoms: Range from painless lumps to neurological deficits, depending on location.
• Types: Include cutaneous, intracranial, intraspinal, intradiploic, oral/head-neck, and genital cysts.
• Causes: Encompass congenital development, trauma, iatrogenic factors, infection (HPV), and rare genetic syndromes.
• Treatment: Surgical excision is the gold standard; laser and observation are options in select cases. Early intervention improves outcomes, and complete removal reduces recurrence.

Understanding the varied presentations and management strategies for epidermoid cysts ensures timely diagnosis and optimal patient care.