Atheroma is a benign skin lesion that appears as a lump under the skin.

Synonyms: Sebaceous cyst

How it develops?

It forms by clogging of the sebaceous gland duct, which in turn causes the sebum to accumulate in the gland itself and around it. A membrane, capsule, then gets formed around the accumulated sebum, containing it, and preventing it from futher expanson.

Symptoms and signs

The first thing that is noticed is a painless bump in the skin, and the most common regions are the head, back, chest, genitals…

It can become inflamed very often. It then turns red, painfull and swollen. Inflammation can sometimes resolve by itself, but more often it will become a purulent infection, which can then be addressed only surgically.

How is it diagnosed?

Diagnosis is easily acquired by clinical examination (by eye), and by palpation of the lump itself, in order to assess the hardness and the size of the lesion. A biopsy is rarely needed.

How is it removed?

If it doesn’t cause any discomfort or esthetic problems, it doesn’t even need to be treated.

But, if it gets infected, it is neccesary to surgically address the issue in some of the following ways:

  1. Incision
  2. Excision
  3. Punch method

Risk factors and prevention

Although atheromas appear in both sexes, they are more common among men, hence a connection with the presence of male sex hormone (testosterone) is considered to exist. The formation of atheromas is associated with extensive sun exposure and sun bed exposure, as is with minimal trauma to the skin in the affected region.

There is no known direct measure of prevention, but persons with the inclination towards formation of atheromas are advised to avoid using body care products that contain oils, because they can cause blockage of the sebaceous ducts and thus facilitate the formation of atheromas.

Also, consulting with Your doctor at a time when the atheroma is not infected or inflamed can be considered as prevention, as it will ease the treatment for the patient.

Frequently asked questions

Do I need to remove it?

No, but it’s our recommendation to remove them in a timely fashion because they tend to get infected and cause problems.

Is it possible to remove an atheroma on the head without a "classic excision"?

Yes, over the last couple of years, we have developed a new removal technique “through 2 mm holes”.

Learn more

Sinonimi: Atheroma cutisSebaceous cyst

They appear as lumps or bumps under the skin, elastic to pressure and free to move in relation to the deeper structures. Most common localization is on the head, back, chest, genitals but they can appear on any other region of the body, except for palms and soles. The unpleasant odour coming from it is a consequence of keratin, a protein produced in the sebaceous gland itself. They go into infection fairly often, and then pain and swelling occur, with a development of a purulent process which finally results in formation of an abscess.

Differential diagnosis

Diagnostically they can be mixed up with lipomas, fibrolipomas and neurofibromas.

Reasons for formation

Sebaceous cysts are formed by blockage of the sebaceous gland ducts or by swelling of the hair follicle which then disrupts the emptying of the sebaceous gland through the pore.

Symptoms and signs

It is usually noticed as a small painless lump that can be felt under the skin. When they last longer (sometimes for years), those lumps can reach the size of hazelnuts or be even bigger. Often they develop purulent infections inside.

Signs of developing purulent infection are .

  • redness,
  • swelling,
  • local increase in temperature of the skin,
  • leaking of smelly, dirty-cheesy like content or pus,
  • pain

How is it diagnosed?

Diagnosis is usually made on the basis of the look of the lesion itself (by eye) and on the basis of information acquired by palpation of the lesion. Biopsyis rarely needed.


In cases of infection development, a purulent abscess is formed, and very rarely, when not treated, necrosis can develop.


Sebaceous cysts that don’t impose any esthetic or functional problems are usually left untreated.

If they disrupt the esthetic appearance and especially of they get infected, they need to be treated in some of the manners :

  • Incision and drainage. In cases of infections, an incision of the skin, in order to drain the purulent content and subside the inflammation, is made. After the inflammation process is resolved, a radical excision is recommended because there is a significant probability of renewing the process.
  • • Total radical excision. This surgical procedure is advised as a permanent solution, but only in cases where there’s no infection present. Radical excision entails the removal of the cyst itself and the surrounding tissue, thus creating a skin defect slightly larger than the cyst itself, and then requires the suture of such wound. Removal of the sutures is done in 7 to 14 days after.
  • Minimal excision. This is a method where a small incision about 5mm in size is made, and the cyst is removed through it, part by part. The wound heals with no sutures, and the scar is minimal.
  • Removal through puncture. This is a special method used primarily for sebaceous cysts on the head.

Risk factors

Sebaceous cysts are most common to appear:

  • After puberty, very rarely they occur before puberty
  • In men, in all regions except for the head (the head is more common for women)
  • In persons who have had acne during puberty
  • After extensive sun tanning or sun bed tanning
  • After trauma to the skin. Usually it’s microtrauma, followed by crusting.


Formation of sebaceous cysts is impossible to prevent. But, persons who already had them are advised to avoid using skin care products that contain oils, as oils can increase the risk of sebaceous duct blockage, and by so, to increase the risk of developing sebaceous cysts.