What are the other Names for this Condition? (Also known as/Synonyms)

• Calcifying Epithelioma of Malherbe
• Pilomatrixoma
• Trichomatricoma

What is Pilomatricoma? (Definition/Background Information)

• Pilomatricoma is a benign and generally slow-growing skin tumor of the hair follicle. It is common and occurs on the skin as a cystic nodule, usually in the head and neck region
• Around 20% of hair follicle tumors are Pilomatricomas. They can occur in children and adults, though a bimodal age distribution pattern is observed
• There are two kinds of Pilomatricomas:
  • Sporadic type of Pilomatricoma, in which a single tumor is observed
  • Familial type of Pilomatricoma, in which multiple tumors are observed. It often occurs in association with genetic conditions, such as Steinert syndrome, Sotos syndrome, myotonic dystrophy, and many others
• The cause of Pilomatricoma is related to genetic factors for both the familial type and sporadic type
• The treatment of Pilomatricoma is based on the signs and symptoms that develop and the presence of underlying conditions (if any). In a majority of cases, no treatment may be necessary for solitary tumors. A simple surgical excision of the tumor is considered curative
• The prognosis for Pilomatricoma is excellent with suitable treatment. However, the prognosis of Pilomatricoma linked to an underlying genetic disorder is dependent upon the severity of the disorder

Who gets Pilomatricoma? (Age and Sex Distribution)

• A bimodal age distribution is associated with Pilomatricoma. It can occur in children and young adults below 25 years of age and in elderly adults above the age of 50 years
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic background may be affected

What are the Risk Factors for Pilomatricoma? (Predisposing Factors)

• Currently, no risk factors have been identified for sporadic Pilomatricoma that occur in a random manner. Nevertheless, certain genetic factors have been implicated with the sporadic types too
• The risk factors for familial Pilomatricoma include the following genetic disorders:
  • Steinert syndrome
  • Turner syndrome
  • Gardner syndrome
  • Sotos syndrome
  • Myotonic dystrophy

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Pilomatricoma? (Etiology)

The cause of development of Pilomatricoma is presently unknown.

• The familial type of tumor is associated with certain genetic conditions and it may be inherited
• Mutation in beta-catenin gene has been observed in the sporadic type of Pilomatricoma

What are the Signs and Symptoms of Pilomatricoma?

The signs and symptoms of Pilomatricoma may include:

• It usually occurs as a single, raised cystic nodule on the skin
• Pilomatricomas are usually well-defined, either skin colored or bluish, and can be very hard
• Multiple tumors are noted in association with other syndromes (underlying conditions)
• It is typically a slow-growing tumor that occurs deep in the skin. Due to this, it is sometimes mistaken for a lymph node
• It can range in size from 0.5 to 3 cm
• The skin over the nodule may ulcerate and bleed
• These nodules can occur at any location in the body, but they are commonly observed in the head and neck region
• The tumors may also calcify

In case of familial Pilomatricoma, the signs and symptoms of underlying genetic disorders will be present.

How is Pilomatricoma Diagnosed?

A diagnosis of Pilomatricoma may involve the following:

• A thorough medical history and physical examination
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Blood tests may indicate increased levels of calcium (hypercalcemia) and parathyroid hormone (PTH)
• A fine needle aspiration may be performed if the nodule is mistaken for a lymph node. This can lead to a misdiagnosis of metastatic squamous cell carcinoma
• Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Specific tests may be undertaken based on the underlying genetic conditions that are associated with inherited forms of Pilomatricoma

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Pilomatricoma?

The complications from Pilomatricoma may include the following:

• Though the tumors are slow-growing, in case of localized hemorrhage, they may become fast-growing, presenting concerns of a malignancy
• The tumors often occur in the head and neck region and may present cosmetic issues in some individuals
• Ulceration and bleeding of the tumors may cause an infection (bacteria or fungi) leading to scarring
• Complications may arise from the inherited genetic disorder associated with multiple tumors

How is Pilomatricoma Treated?

The treatment of Pilomatricoma may involve the following:

• In a majority of cases, solitary tumors may not be removed unless they cause bothersome signs and symptoms such as cosmetic issues. The healthcare provider may chose to maintain regular observation of the tumor growth
• However, rapidly-growing single tumors may be completely excised and removed
• Multiple tumors are associated with genetic disorders, such as Gardner syndrome, Turner syndrome, etc., and these underlying conditions need to be treated accordingly

How can Pilomatricoma be Prevented?

Current medical research has not established a method of preventing both sporadic and familial forms of Pilomatricoma.

• If there is a family history of the following disorders, then genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
  • Steinert syndrome
  • Turner syndrome
  • Gardner syndrome
  • Sotos syndrome
  • Myotonic dystrophy
• In such cases, genetic counseling will help assess risks before planning for a child

Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders.

What is the Prognosis of Pilomatricoma? (Outcomes/Resolutions)

• The prognosis for sporadic Pilomatricoma is excellent with appropriate treatment, since it is a benign tumor
• The prognosis for familial Pilomatricoma depends upon the nature and severity of the underlying genetic condition it is associated with

Additional and Relevant Useful Information for Pilomatricoma:

• A case of a very large Pilomatricoma associated with abnormal calcium metabolism made normal with excision of the cyst was reported in 2006
• There is no evidence to prove that certain foods contribute to Pilomatricoma development
• Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that could potentially worsen the condition
• The presence of dirt on the body is not a causative factor for the condition. However, it helps to be clean and hygienic, which may help the condition from getting worse