Pilomatricoma: experience of the hospital for sick children.

BACKGROUND Pilomatricoma (calcifying epithelioma of Malherbe) is a common skin neoplasm in the pediatric population that is often misdiagnosed as other skin conditions or tumours. OBJECTIVES The objective of the present retrospective study was to review the clinical and histopathological presentation of this neoplasm in children. METHODS The records of the pathology department at The Hospital for Sick Children, Toronto, Ontario, were searched for all cases of pilomatricoma between 2001 and 2006. The records of these patients were reviewed to determine sex, age, location and size of the tumour, pathological features and recurrence rate. All patients underwent surgical excision of the lesions. RESULTS A total of 93 lesions in 85 patients were identified. The median age was 8.7 years. Of the 85 patients diagnosed with pilomatricoma, 44 (52%) were female. In all cases, the initial presentation was an asymptomatic, slow growing, superficial hard mass with bluish discolouration. The most common sites of occurrence were the face (48%), neck (21%) and upper limbs (18%). The size of the surgical specimens collected ranged from 0.1 cm to 2.6 cm. The diagnosis was confirmed by histopathological examination in all cases. Ghost cells and basaloid cells were described in most of the cases (83%). There were no recurrences in this series. CONCLUSIONS This entity should be considered with other benign or malignant conditions in the clinical differential diagnosis of solitary firm skin nodules, especially those on the face, neck and upper limbs. The diagnosis can generally be made by clinical examination. The treatment of choice is surgical excision, and the recurrence rate is very low.