This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Pilomatrixoma is a benign (non-cancerous) skin tumor of the hair follicle (structure in the skin that makes hair). They tend to develop in the head and neck area and are usually not associated with any other signs and symptoms (isolated). Rarely, pilomatrixomas can become cancerous (known as a pilomatrix carcinoma). Although they can occur in people of all ages, pilomatrixomas are most commonly diagnosed in people under age 20. The exact underlying cause is not well understood; however, somatic changes (mutations) in the CTNNB1 gene are found in most isolated pilomatrixomas. Rarely, pilomatrixomas occur in people with certain genetic syndromes such as Gardner syndrome, myotonic dystrophy, and Rubinstein-Taybi syndrome; in these cases, affected people usually have other characteristic signs and symptoms of the associated condition. They are usually treated with surgical excision.
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