[Pilomatrixoma or Malherbe's calcifying epithelioma. A case report and review of the literature].

The case of a upper extremity calcifying epithelioma of Malherbe in a 16-year-old boy is reported. Clinical and pathological features of this extremely rare tumour, arisen from hair cortex cells, are reviewed. Pilomatrixoma has been reported not only as a benign lesion, or as a low-grade malignant lesion with a tendency to recur locally, but also as a highly malignant tumour. Factors influencing clinical differential diagnosis and prognosis are discussed as well.