Table of ContentsView AllTable of ContentsSymptomsCausesTreatmentShould You Pop It?RemovalDo They Come Back?
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Treatment
Should You Pop It?
Removal
Do They Come Back?
Apilar cyst, also known as atrichilemmalcyst, is around bumpfilled withkeratinthat forms from the outer hair follicle root sheath.
Pilar cysts are sometimes calledsebaceousorepidermoidcysts, but there are differences between them. While pilar cysts come from the outer root sheath,sebaceousor epidermoid cysts originate from another area of the skin orhair follicle.
About 10% of the population has a pilar cyst. They can occur anywhere on the body, but over 90% of pilar cysts are found on the scalp. They are benign (noncancerous) and very rarely become malignant (cancerous).
This article will discuss what pilar cysts are, what causes them, whether they need to be removed, and what the removal procedure entails.
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Pilar Cysts: How Scalp Cysts Feel
A cyst is a growthunder the skinthat has a lining and contents that are liquid or semi-solid. Pilar cysts contain materials made up of keratin. The contents resemble white toothpaste.
What Is Keratin?Keratin is a protein that makes up, and helps maintain, hair, skin, and nails.
What Is Keratin?
Keratin is a protein that makes up, and helps maintain, hair, skin, and nails.
A pilar cyst feels like a smooth, round, firm nodule that is mobile (movable when touched). A pilar cysts looks like epidermoid cysts but does not have apunctum(a small opening on the surface of the cyst).
Pilar cyst nodules measure about 0.2 inches to 2 inches in diameter. There may be multiple cysts present or just one. They aren’t typically painful but may cause pain if they areinflamed.
Pilar Cyst vs. Epidermoid CystTo the naked eye,epidermoid cystsand pilar cysts look quite similar, but they are not the same.The main difference between an epidermoid cyst and a pilar cyst is that under a microscope, the lining of an epidermoid cyst looks like the epidermis (the outer layer of skin). In contrast, the lining of a pilar cyst consists of cells like those in hair roots.Other differences include:Location: Pilar cysts are usually found on the scalp. Epidermoid cysts are commonly found on the face, neck, and trunk.Punctum: Epidermoid cysts have a central punctum; pilar cysts do not.Origin: Epidermoid cysts originate from the epithelium orhair folliclecavity. Pilar cysts originate from the outer root sheath.Cyst wall: Epidermoid cyst walls are delicate and prone to rupture. Pilar cyst walls are thick and rupture less easily.Granular layer: Epidermoid cysts have a granular layer; pilar cysts do not.
Pilar Cyst vs. Epidermoid Cyst
To the naked eye,epidermoid cystsand pilar cysts look quite similar, but they are not the same.The main difference between an epidermoid cyst and a pilar cyst is that under a microscope, the lining of an epidermoid cyst looks like the epidermis (the outer layer of skin). In contrast, the lining of a pilar cyst consists of cells like those in hair roots.Other differences include:Location: Pilar cysts are usually found on the scalp. Epidermoid cysts are commonly found on the face, neck, and trunk.Punctum: Epidermoid cysts have a central punctum; pilar cysts do not.Origin: Epidermoid cysts originate from the epithelium orhair folliclecavity. Pilar cysts originate from the outer root sheath.Cyst wall: Epidermoid cyst walls are delicate and prone to rupture. Pilar cyst walls are thick and rupture less easily.Granular layer: Epidermoid cysts have a granular layer; pilar cysts do not.
To the naked eye,epidermoid cystsand pilar cysts look quite similar, but they are not the same.
The main difference between an epidermoid cyst and a pilar cyst is that under a microscope, the lining of an epidermoid cyst looks like the epidermis (the outer layer of skin). In contrast, the lining of a pilar cyst consists of cells like those in hair roots.
Other differences include:
Why Do Pilar Cysts Form?
Pilar cysts form when there is a buildup of keratin in the skin pore. This blocks the removal of sebaceous gland secretions, causing keratin material to build up, leading to theformation of a cyst.
Females in middle adulthood are the group most commonly diagnosed with pilar cysts.These cysts can be sporadic (appear randomly in a population) but also run in families. Pilar cysts have anautosomal dominantinheritance pattern, meaning if a parent has it, there is a 50% chance their child will inherit it, regardless of the child’s sex.
People genetically predisposed to pilar cysts tend to develop them at a young age and often have multiple cysts at a time.
Cyst vs. Tumor: What Are the Differences?
Do Pilar Cysts Always Need to Be Removed?
Unless they are causing problems, pilar cysts do not need to be removed. They are not dangerous. If they aren’t bothering you, leaving them be is OK.
Occasionally, complications can arise, such as:
You may choose to have the pilar cyst removed to treat or prevent complications.
Other reasons you may want to have a pilar cyst removed include:
Common Dilemma: To Pop or Not to Pop Pilar Cysts
Do not pop, squeeze, or burst any type of skin cyst. Doing so can lead to the development or spread of infection. If you want to “deflate” your cyst, see aqualified healthcare professionalto have it drained or removed.
Pilar Cysts Removal Procedure
Surgical procedures for pilar cyst treatment can involve one of two methods, as follows:
These procedures are performed using local anesthesia.
Medicareor private insurance may cover the removal cost if it is deemed medically necessary rather than cosmetic.
Costs vary, ranging from the low hundreds to the low thousands. Contact the surgery provider and your insurance carrier for an exact cost estimate.
Scalp Acne vs. Pilar Cysts
Acneis an inflammatory skin disorder involving the growth of bacteria stemming from clogged hair follicles. Acne causes lesions such as:
Do Pilar Cysts Come Back?
Pilar cysts that resolve on their own tend to recur. Surgical removal of the entire cyst decreases the likelihood that the cyst will return.
With surgical treatment, if theentire cyst, including the sac, is not removed, the cyst may return.It is also common for new pilar cysts to form later on, even if the cyst that was removed stays gone.
Summary
Pilar cysts are keratin-filledbumpsthat usually form on the scalp. They originate from the outer hair root sheath. Pilar cysts form when keratin builds up in a blocked skin pore. They can develop spontaneously or be inherited from a parent.
Pilar cysts do not need to be removed unless they are causing problems. They may resolve on their own. Surgical removal of the entire cyst is the most effective way to reduce the likelihood of the cyst returning. Never pop or drain a cyst on your own. Always see a healthcare provider.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.DermNet.Trichilemmal cyst.Bejjanki K, Mishra D, Kapoor A.Trichilemmal cyst of eyelid: A case report and review of literature.Indian J Ophthalmol Case Rep. 2022;2(1):214. doi:10.4103/ijo.IJO_783_21Varghese R, Yabit F, Alrifai A, Burns A, Boucher B, Tiesenga F.Pilar cysts of the head and neck: a case report.Cureus. 2022;14(4):e23932. doi:10.7759/cureus.23932British Association of Dermatologists.Cysts – epidermoid and pilar.Primary Care Dermatology Society.Pilar cyst (syn. trichilemmal cyst).American Academy of Dermatology Association.Incysting on understanding pilar cysts.National Health Service.Skin cyst.Centers for Medicare & Medicaid Services.Removal of benign skin lesions.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Acne.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.DermNet.Trichilemmal cyst.Bejjanki K, Mishra D, Kapoor A.Trichilemmal cyst of eyelid: A case report and review of literature.Indian J Ophthalmol Case Rep. 2022;2(1):214. doi:10.4103/ijo.IJO_783_21Varghese R, Yabit F, Alrifai A, Burns A, Boucher B, Tiesenga F.Pilar cysts of the head and neck: a case report.Cureus. 2022;14(4):e23932. doi:10.7759/cureus.23932British Association of Dermatologists.Cysts – epidermoid and pilar.Primary Care Dermatology Society.Pilar cyst (syn. trichilemmal cyst).American Academy of Dermatology Association.Incysting on understanding pilar cysts.National Health Service.Skin cyst.Centers for Medicare & Medicaid Services.Removal of benign skin lesions.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Acne.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
DermNet.Trichilemmal cyst.Bejjanki K, Mishra D, Kapoor A.Trichilemmal cyst of eyelid: A case report and review of literature.Indian J Ophthalmol Case Rep. 2022;2(1):214. doi:10.4103/ijo.IJO_783_21Varghese R, Yabit F, Alrifai A, Burns A, Boucher B, Tiesenga F.Pilar cysts of the head and neck: a case report.Cureus. 2022;14(4):e23932. doi:10.7759/cureus.23932British Association of Dermatologists.Cysts – epidermoid and pilar.Primary Care Dermatology Society.Pilar cyst (syn. trichilemmal cyst).American Academy of Dermatology Association.Incysting on understanding pilar cysts.National Health Service.Skin cyst.Centers for Medicare & Medicaid Services.Removal of benign skin lesions.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Acne.
DermNet.Trichilemmal cyst.
Bejjanki K, Mishra D, Kapoor A.Trichilemmal cyst of eyelid: A case report and review of literature.Indian J Ophthalmol Case Rep. 2022;2(1):214. doi:10.4103/ijo.IJO_783_21
Varghese R, Yabit F, Alrifai A, Burns A, Boucher B, Tiesenga F.Pilar cysts of the head and neck: a case report.Cureus. 2022;14(4):e23932. doi:10.7759/cureus.23932
British Association of Dermatologists.Cysts – epidermoid and pilar.
Primary Care Dermatology Society.Pilar cyst (syn. trichilemmal cyst).
American Academy of Dermatology Association.Incysting on understanding pilar cysts.
National Health Service.Skin cyst.
Centers for Medicare & Medicaid Services.Removal of benign skin lesions.
National Institute of Arthritis and Musculoskeletal and Skin Diseases.Acne.
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