Malignant pilomatricoma: two new observations and review of the relevant literature.

Malignant pilomatricoma or pilomatrical carcinoma is a rare malignant hair follicle neoplasm. This tumor is locally aggressive with increased tendency to recur, but a low metastatic potential. Its histopathological diagnosis is difficult and based on a detailed evaluation of the infiltrative nature, the importance of the mummified and necrotic cell component, atypical mitoses, and perineural or vascular invasion. Surgical wide resection is the recommended treatment. It reduces the risk of focal recurrence by 50%. Here we report two new cases including one that occurred on a lesion initially diagnosed as benign pilomatricoma.