What is an atheroma?

An atheroma appears as a five to twenty millimeter large node under the skin. There are many terms that have the same meaning. The most common terms include infundibular cyst, epidermal cyst, epidermal cyst, epidermal cyst, epithelial cyst, epidermal inclusion cyst, epidermoid cyst, retention cyst, inclusion cyst, epithelial cysts and epidermoid horn cyst. In the vernacular the terms groats pouch, semolina pouch, bellows tumor and skin cyst are often used. The names sebaceous nodules, sebaceous cyst and sebaceous gland cyst are not entirely correct, since it is not a blocked excretory duct of a sebaceous gland. An atheroma is caused, among other things, by a blockage of the funnel-shaped opening of the hair follicle (infundibulum). Epidermal inclusion cysts can occur in any area of the body. Atheromas are particularly common on the face, neck, chest and back. The intimate area, fingers and cheek mucosa can also be affected. The cyst contains malodorous peeled off horn material and fat. The cyst content is surrounded by a capsule. The envelope of an atheroma is structured like the cell layer of the epidermis (epidermal squamous epithelium). Therefore the name epidermoid cyst is derived. Atheromas can remain unchanged for years or change in size.


How common are atheromas?

Atheromas are the most common benign skin changes. 85 to 90 percent of all removed cysts are grotto sacs (Murray JC, et al. Benign skin tumors. 1997. plastic, maxillofacial, and reconstructive surgery. Williams & Wilkins). Epidermoid cysts typically occur in the third and fourth decade of life. The occurrence of prepubescent pouches is very rare. Men are affected significantly more often than women (ratio 2:1).


Are atheromas dangerous?

Atheroma pouches are harmless, benign and not contagious. They do not spread to other parts of the body and do not cause serious problems. Therefore an atheroma does not need to be removed. Even harmless skin lesions can change in extremely rare cases. There are very few case reports of malignant degeneration worldwide. Therefore, an assessment of the risk has only a very limited significance.

The development to light skin cancer (squamous cell carcinoma) is approximately 1:10,000 (Morgan MB, et al., 2001, Br J Dermatol). There is therefore no reason for concern. Frequently recurring swellings that increase rapidly in size, are larger than two centimeters in diameter, bleed or are accompanied by a change in skin color should be examined by a dermatologist. A histological examination is only necessary in justified suspicious cases (Gargya V, et al., 2017, Ann Plast Surg; Jeyakumar R. Apollos, et al., 2017, Ann Med Surg).

Trichilemmal cyst - a strange bump on the head

Trichilemmal cysts are very similar to atheromas and are the second most common form of a skin cyst. It is a slowly growing bulge of one to two centimeters in size, mainly on the scalp. The nodules are firm and well defined. The overlying skin can be moved easily. Trichilemmal cysts are also called false atheromas, tricholemmal cysts and pilar cysts. The lining consists of cells (stratified squamous epithelium) as found on the outer hair root sheath. In contrast to atheromas, the lining of trichilemmal cysts does not have a granule cell layer (stratum granulosum). On closer inspection, another difference becomes apparent. Unlike groats bags, there is no black spot on the skin surface of trichilemic cysts. The cyst contains less fat and more keratin compared to inclusion cysts of the epidermis. The cyst content is hard, firm and odorless. Trichilemmal cysts usually do not cause any complaints. Pain in the affected area is only possible in case of injury or inflammation. Young women are more affected than men. The predisposition to the development of trichilemmal cysts can be hereditary in rare cases. In these cases, the probability of an affected child in an affected parent is one in two (autosomal dominant inheritance pattern).


How does an atheroma develop?

Atheromas can have different causes. If the skin is injured, for example by a piercing, cells of the skin surface can get under the skin. The cells of the outermost skin layer (keratinocytes) form the horn of the skin (keratin). If the cells of the skin surface produce horn under the skin, a grotto bag is formed. Since this is a retention of exfoliated skin cells, atheromas are also called inclusion cysts, retention cysts or epidermoidal horn cysts. Horny cysts occasionally develop on the earlobe after piercing an ear hole. When the ear hole grows and the skin encapsulates itself, a lump is formed on the earlobe. Such nodules can develop in principle everywhere, where a piercing is pricked in the face or at the navel. In most cases atheromas are caused by a blockage of the hair follicle of the scalp, which is occasionally visible as a black spot. The exact reasons for the blockage are still unclear. Sebum deposits or enlarged sebaceous glands (sebaceous gland hyperplasia) do not play a role in the development of semolina nodes. The atheroma contains skin secretions, i.e. horn and fat. The cyst contains a foul-smelling white, crumbly mass that looks like "groats" or "semolina". Occasionally the term "sterile pus" is used to describe the contents of the cyst. An accumulation of pus in a tissue cavity is called an abscess. Pus is formed when the body defends itself against germs. The term "sterile pus" is therefore a contradiction in terms. Germs play no role in the development of semolina knots. In rare cases, bacteria can penetrate an atheroma and multiply. The risk of inflammation is particularly high when an attempt is made to express the atheroma. When an inflammation occurs, the atheroma swells, becomes red, painful and feels warm.

If atheromas develop before puberty, in unusual numbers and in unusual places such as the hands or feet, very rare hereditary diseases can be the cause (Gardner syndrome, Gorlin syndrome, Favre-Racouchot syndrome). It is believed that prolonged sun damage favors the development of atheroma. Evidence suggests that certain viruses play a role in the development of grotesque bags (Ramagosa R., et al, 2008, J Am Acad Dermatol). Atheroma may also occur as a rare side effect of certain immunoregulatory drugs (imiquimod, cyclosporine).

What complaints/symptoms do atheromas cause?

As a rule, atheromas do not cause any complaints. Often affected people are disturbed by the appearance of a bump on the head or a lump on the back. The bumps feel hard. The overlying skin can usually be moved a little. Groat bags are about half a centimeter to two centimeters in size. Epidermoid cysts can form anywhere, especially on the face, neck, chest, back and intimate areas. On closer inspection, a black spot can occasionally be seen on the surface of the skin. Pain is the exception. When an atheroma is injured, an unpleasant smelling, yellow-white, viscous paste is released. It cannot be predicted if and when a grotto bag will enlarge, become inflamed or recede on its own.


What helps with atheroma?

The effect of ointments or creams used to treat atheroma has not been proven. Tea tree oil is effective against a variety of germs and bacteria and is usually well tolerated in the right dilution. If opened and emptied alone, groats bags often return. It is therefore strongly discouraged to squeeze or pierce them before opening. Attempting to remove, cut out or puncture an atheroma by yourself carries a high risk of inflammation.


Which doctor treats atheroma?

Many affected persons wish to have an atheroma operation for cosmetic reasons. Especially in the case of atheroma of the face, décolleté or vagina, many attach importance to a barely visible scar. For the removal of a grotto bag on the head, many therefore turn to experienced surgeons. Fine sutures and a gentle surgical technique help to ensure that the operation of a groin pouch in the genital area or an atheroma on the forehead leaves fine scars. When removing benign skin changes, a specialist in plastic and aesthetic surgery always pays attention to the goal of achieving an aesthetically pleasing result. Plastic surgeons are usually used to operating with optical magnifying aids. This is also an advantage when removing skin alterations. If remnants of the grotto sac remain in the wound when an atheroma is removed, the cyst may recur. With the help of magnifying glasses, the tissue can be closely examined to prevent the recurrence of the atheroma.


Atheroma after piercing?

Atheroma can be caused by injury to the skin, especially when piercing an ear hole. The piercing of a piercing can cause cells of the uppermost skin layer to be transplanted under the skin. Dead skin cells and skin fat collect in a tissue cavity. Externally there is a lump to recognize.


Why should an atheroma be treated?

Many patients would like to have atheromas removed because they are unattractive or cosmetically disturbing. Atheromas can easily be seen on the face. In certain areas of the head, patients can get stuck on the atheroma with a hairbrush or comb. Removal is necessary if the atheroma becomes infected. If an atheroma becomes infected, an abscess may develop. Removal of an atheroma is medically necessary if there is redness of the skin, swelling, throbbing pain, overheating or pus formation.


How is an inflamed atheroma treated?

An inflamed sebaceous cyst or an infected atheroma should be cleaned promptly during an operation. Treatment with antibiotics alone is usually not effective. The side effects of antibiotics include intolerance and the development of resistant germs. After removal of the cyst contents, the wound should be closed in such a way that wound secretion can still drain away. Under certain circumstances, it may be advisable to wait for the wound to heal from the depths (secondary wound healing).


Patients usually bear the costs themselves

Atheromas are not dangerous to your health. An atheroma is a benign skin tumor that has nothing to do with the diagnosis of cancer. Nevertheless, an atheroma can be visually disturbing or perceived as annoying. In the opinion of the social courts, in order for health insurance companies to cover the costs, there must be an "abnormal body condition", "impaired function" and the "necessity of medical treatment". The low probability of inflammation and the generally favorable chances of success of the treatment of an inflamed atheroma do not justify a preventive removal. The costs for the removal of an atheroma for aesthetic reasons are usually not covered by health insurance.


How is an atheroma removed?

An atheroma is removed on an outpatient basis and under local anesthesia. During the consultation all precautions are taken for your comfort and safety. The skin is numbed with a fine needle. An anesthetic solution with adrenaline is used to prevent the development of bruises. Careful injection of the atheroma is important for a gentle and painless surgical technique. Best visibility with an optical magnification is important to remove the atheroma "in one piece", "en bloc" or as a whole. Complete removal of the cyst with the cyst wall intact reduces the risk of the groin bag returning. For optimal cosmetic results, the skin incision is aligned along the so-called skin tension lines. An atraumatic fine wound closure is an important prerequisite for fine scar healing. Depending on where the atheroma was removed, the stitches are removed after five to fourteen days. Depending on the affected body part and profession, incapacity to work lasts only a few days. If the removal is carried out for aesthetic reasons, a certificate of incapacity to work (sick note) may not be issued.


What does the removal of an atheroma cost?

The cost of removing an atheroma is calculated according to the effort involved. The cost of an atheroma operation depends on the size and location of the body. On our cost page we inform about the magnitude of the prices of our services.


Author's note

Author: PD Dr. Stéphane Stahl. There are no financial relationships with the pharmaceutical or medical device industries that could have influenced the above text. Any reproduction, even partial, is only permitted for personal use. All texts used on this website are protected by copyright.


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