Characterizing pilomatricomas in children: a single institution experience

Pilomatricomas, or calcifying epitheliomas of Malherbe, are among the most common superficial cutaneous soft tissue lesions in children. Familiarity with the presenting signs and symptoms allows for the diagnosis to be made on physical examination alone in most patients, avoiding expensive and unnecessary diagnostic imaging.

A retrospective IRB-approved review of surgical pathology archives and medical records of all patients undergoing excision of pilomatricomas between 1982 and 2010 was performed to determine the characteristics of the pilomatricoma tumors. Data regarding gender, age, location, size of tumor, and histopathology were collected.

There were 916 pilomatricomas resected in 802 patients. Fifty-five percent of the patients were girls (441 patients). The median age at the time of resection was 6 years (range 5 months to 18 years). Multiple lesions were found in 43 patients (5%). The most common location was head and neck (n = 529, 58%), followed by upper limbs (n = 214, 23%), trunk (n = 130, 14%), and lower limbs (n = 43, 5%). Information on size was available for 674 lesions; mean lesion diameter was 14.0 ± 7.4 mm. Twenty-eight patients (3%) had either recurrent (n = 11) or metachronous (n = 17) lesions resected at our institution, with a median interval of 12 months after initial resection (range 5 weeks to 5 years). No cases of pilomatrix carcinoma were observed.

The majority of pilomatricomas occur in the head and neck, although they can present in any location. Approximately 5% of children have multiple lesions. Pilomatricomas occur slightly more commonly in girls, and 66% of lesions occur in children < 10 years of age. Complete surgical excision is necessary to prevent recurrence. Recurrences and pilomatrix carcinoma are very rare if complete excision is achieved.