Pilomatrixomas

Synonyms

Calcified epithelioma of Malherbe

Definition

A rare, benign tumor originating from the matrix of the hair root.

Etiology

The exact etiology is uncertain; however, mutation in the gene encoding betacatenin (CTNNB1) has been described as a cause of tumor growth in the hair follicle. It can occur almost anywhere on the body but has a propensity to occur in the head and neck region, often involving the eyelid or eyebrow. It is most commonly seen in children and adolescents and with a female predominance (Albert and Jakobiec 2008; Levy and Ilsar 2008; Shields and Shields 2008).

Clinical Presentation

Typically presents as a solitary, firm, nontender, dermal or subcutaneous nodule, freely movable covered by normal, pink, or bluish skin. Usually slow growing over months or years but can occasionally exhibit rapid growth. Multiple pilomatrixomas have been observed, mainly in association with myotonic dystrophy (Albert and Jakobiec 2008; Shields and Shields 2008).

Diagnostics

Pilomatrixo...