Pilomatricoma in children: common but often misdiagnosed.

A pilomatricoma, also known as pilomatrixoma or calcifying epithelioma of Malherbe, is a benign skin tumor arising from the hair follicle matrix. This tumor is common in children and young adults, especially in the head and neck region. However, pilomatricomas are frequently misdiagnosed or not recognized. The history is typical of a slowly enlarging mass, irregularly contoured, it is fixed to the skin but slides freely over the, underlying tissues, often with a discolouration which varies from red to purple-bluish. Ultrasound examination, MRI-scan and fine-needle aspiration can be helpful if the diagnosis is uncertain. Spontaneous regression has never been observed and malignant degeneration is very rare. Surgical excision with clear margins is the treatment of choice, otherwise recurrence may occur due to incomplete resection.