Use of ultrasound in the diagnosis and follow-up of childhood pilomatrixoma.

Aim. Pilomatrixomas are slow-growing benign, deep dermal or subcutaneous tumours deriving from hair matrix cells. The ultrasonographic findings have recently been defined and correlated with the histopathology of the pilomatrixoma. Some authors have reported the sonographic diagnosis of pilomatrixoma as a useful, non invasive test with an elevated diagnostic accuracy. Methods. A retrospective study was carried out on 30 cutaneous nodules, clinically diagnosed as pilomatrixomas, observed in 26 children, during a 3-year period, at the Unit of Paediatric Dermatology. The aim of the study was to evaluate the accuracy of ultrasound examination both in the diagnosis and in the follow-up of pilomatrixomas. All the lesions were submitted to one or more ultrasound scans at the Unit of Radiology of the University Hospital ''S. Orsola-Malpighi'' in Bologna. Results. Of the 30 clinically suspected pilomatrixomas, ultrasound examination supported the clinical diagnosis in 29 instances (96.6%). Surgical excision and histopathological analysis was necessary only in one patient. The other patients were monitored for 1 year with clinical examinations and sonographies, thus avoiding the need for surgical asportation in 90.9% of cases. Conclusion. In conclusion we observed that ultrasound not only represents a procedure useful for the diagnosis of pilomatrixoma, but is also a valid aid in following up the course of the lesion, without surgical intervention.