Use of ultrasonography in the diagnosis of childhood pilomatrixoma.

Pilomatrixomas are relatively common childhood tumors that usually occur in the head and neck region. The clinical diagnosis of these lesions may be difficult, especially if the examining physician is unfamiliar with them. Excision is usually recommended, as a foreign body reaction due to calcification of the lesion may occur and cause a vigorous inflammatory response with risk of scarring. A retrospective study was carried out by examining the preoperative ultrasound scans of 28 suspected pilomatrixomas in 25 children. The findings on sonography were correlated with the histologic results in 19 cases (18 pilomatrixomas and one ruptured epidermoid cyst). In the majority of patients, sonography either correctly supported or excluded the clinical diagnosis of pilomatrixoma and contributed to appropriate preoperative assessment and subsequent management of the lesion. We therefore found sonography of suspected pilomatrixomas in children to be a useful and noninvasive procedure, offering a significant improvement in the accurate diagnosis of these lesions.