What are the aims of this leaflet?
This leaflet has been written to help you understand the term pilomatricoma. It will explains what a pilomatricoma is, what can be done about it, and where more information can be found.
What is a pilomatricoma?
A pilomatricoma is a benign (non-cancerous) growth arising from the cells at the base of hair follicles. Hair follicles are specialised structures in the skin where hair grows from. Pilomatricoma has also been called a pilomatrixoma, trichomatricoma or a ‘calcifying epithelioma of Malherbe’.
What causes a pilomatricoma?
The cause of pilomatricoma is now known to be due to a localised mutation in a hair matrix cell. An overactive proto-oncogene called BCL-2 suggests the normal process of cell death is suppressed, and mutations in CTNNB1 in most cases suggest loss of regulation of a protein complex called beta-catenin/LEF-1.
Are pilomatricomas hereditary?
Most pilomatricomas do not run in families, but very rarely (less than 1 in 100,000) there may be a link to rare (less than 1 in 10,000) genetic disorders.
What are the symptoms of pilomatricoma?
A pilomatricoma does not normally cause any symptoms unless it becomes inflamed or infected, when it becomes red and sore. Occasionally the growth may burst and release white and yellow chalky fluid. Pilomatricomas can sometimes be uncomfortable.
What does a pilomatricoma look like?
A pilomatricoma normally appears as a single pink or purplish lump containing white areas. The white areas are due to calcium (chalky) deposits and makes the lump feel hard and bony.
They are usually less than 3 cm in diameter, although rarely they can be larger. They are most common on the head and neck or the upper body in children and teenagers, but can develop anywhere on the body at any age.
How is a pilomatricoma diagnosed?
Your doctor may suspect the diagnosis on examining the skin and may refer you for an ultrasound scan. The diagnosis is confirmed by an examination of a small tissue sample: a biopsy – when a tiny piece of skin is removed under local anaesthetic.
Can a pilomatricoma be cured?
Yes, if a pilomatricoma is completely removed surgically (cut out), it is considered to be cured. It is very unlikely that they will grow back after being removed. They do not tend to go away by themselves and will either stay the same size or slowly grow over the years.
How can a pilomatricoma be treated?
The normal treatment for a pilomatricoma is to completely remove the lump surgically with a procedure known as ‘excision’.
Self care (What can I do?)
There is nothing you can do to prevent it occurring but, to prevent it becoming inflamed or infected, you should not pick or squeeze the lesion.
Where can I get more information about pilomatricomas?
Web links to detailed leaflets:
Links to patient support groups:
There are no specific patient support groups for this condition.
For details of source materials used please contact the Clinical Standards Unit (email@example.com).
This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.
This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel
BRITISH ASSOCIATION OF DERMATOLOGISTS
PATIENT INFORMATION LEAFLET
PRODUCED FEBRUARY 2014,
UPDATED MARCH 2017, DECEMBER 2021
REVIEW DATE DECEBER 2024