Is a dermatologic issue featuring growths that originate from hair follicles.

This condition consists of a neoplasm (an abnormal growth of tissue) that affects an adnexa of the skin.

The “adnexa” refers to anatomical structures adjunct to an organ. Sometimes people use the term “appendage” instead.

When it comes to the skin, its “adnexa” or “appendages” include sebaceous glands, eccrine sweat glands, apocrine glands, and hair follicles.

Trichoepithelioma is a benign growth that looks like Carcinoma of the skin, but it’s not a significant threat to the health of a patient.

The difference is that such tumors lack myxoid stroma and sometimes they don’t even have mitoses.

It is a rare condition that results in the development of single or multiple growths/tumors on the skin.

These tumors are usually small (less than a centimeter), rounded, firm, and shiny. And they increase in number as the patient ages.

The visual confirmation of Trichoepithelioma is something more evident in female patients.

In the US, a dermatopathology laboratory reports two to three cases per year.

Trichoepithelioma Causes

Some researchers consider Trichoepithelioma as an inherited condition caused by an autosomal dominant trait, which means men and women have equal chances of suffering from this disease.

According to some medical experts, the cause of Trichoepithelioma originates from a gene located in the band 9p21, which plays a significant role in the inhibition of the cell-cycle function.

The purpose of the cell-cycle is accurately duplicating the DNA structure found in the chromosomes, to make two exact copies of the genetical material to produce two new cells with these very same genes.

When the chromosome band 9p21 gets altered or damaged, the cells keep multiplying uncontrollably, and the excess of cells forms a growth.

Other medical experts consider some cases to be related to the mutations of the Cylindromatosis Oncogene (CYLD).

Under normal circumstances, this gene provides instructions for making a protein that helps to protect healthy cells from apoptosis.

Apoptosis refers to the programmed and regulated process that leads cells to self-destruct, eliminating old or unnecessary cells so the body may replace them with new or healthy ones.

A 2006 study suggested that abnormalities in the CYLD gene could result in either Brooke-Spiegler Syndrome, Familial Cylindromatosis, or Trichoepithelioma.

A 2009 study reported that mutations in the CYLD gene produced some cases of Trichoepithelioma featuring multiple growths/tumors on the skin.


The primary sign of Trichoepithelioma is the growth of small tumors with the following features:

  • Skin-colored
  • Rounded, firm, and shiny
  • 2-8 mm in diameter
  • Nearly half of the tumors grow on the face and scalp
  • Rare ulcerations occur sometimes
  • Growths occasionally appear on the neck and vulva

Trichoepithelioma Diagnosis

When medical experts seek to confirm the presence of this condition in a patient, they often have to rely on physical examination as well as other laboratory tests.

Some of the most common diagnostic procedures in these particular cases are listed here below:

  • Physical Examination: doctors seek to differentiate the tumors from other skin growths. Given the hereditary nature of this condition, many perform this test along with a medical history focusing on the family.
  • Genetic Studies: looking for abnormalities in the gene coding of the chromosome band 9p21 could help medical experts to confirm Trichoepithelioma.
  • Biopsy: taking a sample of tissue from the growths to study its characteristics or histology, find out if the tumor is benign or malignant, and differentiate this condition from Carcinoma.

Trichoepithelioma Treatment

Some studies highlight the potential benefits of the Anti-tumour necrosis factor alpha (Anti-TNF-α) therapy, which relies on an antibody that suppresses the response to a protein that causes inflammation.

The same researchers suggested the use of the Mammalian Target of Rapamycin (mTOR), a protein that could destroy cancerous cells.

But, more often than not, the most common treatment for Trichoepithelioma is surgery.

Here’s a list of the most common surgical procedures used to treat Trichoepithelioma:

  • Surgical removal: surgeons can perform the excision of singular tumors, but it’s not a good choice to deal with multiple growths.
  • Laser Surgery: doctors use carbon dioxide or other similar compounds to remove the tumors.
  • Split-thickness skin grafting: it refers to the removal of the skin layers containing the tumors and replacing them with healthy skin from other parts of the body.
  • Dermabrasion: it consists of the removal of the upper layers by using abrasive materials.

All of these processes have varying degrees of success in dealing with Trichoepithelioma. And some of them might lead to permanent scarring.

Still, both doctors and patients confirm that, more often than not, the results are a lot better than the physical effects of Trichoepithelioma.