Pilomatrixoma Clinical Presentation

Updated: Oct 13, 2020
  • Author: Jaggi Rao, MD, FRCPC; Chief Editor: Dirk M Elston, MD  more...
  • Print


Patients usually present with a solitary, firm, nontender subcutaneous nodule that has been slowly growing over several months or years. Patients are usually asymptomatic, but some report pain during episodes of inflammation or ulceration. Rapid growth is rare, but reports indicate one lesion reaching 35 mm in 8 months and another reaching 1 cm in 2 weeks. Occurrence in more than one member of the same family is rare and is usually observed in association with myotonic dystrophy.


Physical Examination

Approximately 50% of the lesions occur on the head and neck, especially the cheek, preauricular area, eyelids, forehead, scalp, and lateral and posterior neck. [27, 28, 29] Eyelid lesions may mimic chalazion. [30] Lesions can also occur on the upper and lower extremities and trunk. [31] One lesion was observed in the middle ear and another in the ovary. [32, 33]

Most lesions measure 0.5-3 cm, but, rarely, giant lesions up to 15 cm are reported. Patients usually have a single, firm, stony, hard nodule. Lesions are usually the color of the normal skin, but reddish-purple lesions have been observed (probably resulting from hemorrhage). Stretching of the overlying skin can give the lesion a multifaceted, angulated appearance known as the "tent sign," likely due to calcification in the lesion. In a review of 137 pediatric patients, tumors occurred predominantly on the face or neck (70%) and upper extremities (22%). [34]

One lesion showed the "dimple sign," which is often associated with dermatofibromas. Unusual morphological variants include perforating, cystic, bullous, lymphangiectatic, hornlike, keratoacanthomalike, pigmented, and lesions that show anetodermalike changes on the surface. [35, 36, 37, 38]