Pilomatrix carcinoma: More malignant biological behavior than was considered in the past.

Pilomatrix carcinoma is a very rare malignancy, with ~130 cases reported in the literature. In the past, pilomatrix carcinoma was considered to be a low-grade malignant tumor. Currently, however, its significant recurrence and metastatic potential has been well documented. Lymph node and systemic metastases are frequently observed. Wide surgical excision of the primary lesion is the principal modality of treatment, whereas adjuvant radiotherapy may be beneficial in local tumor control. Lymph node metastases may be treated surgically or with radiotherapy. Systemic disease is not responsive to chemotherapy, and is hence associated with a poor prognosis. Since the majority of nodal and systemic metastases present after the initial diagnosis and treatment, follow-up examinations of these patients may be warranted, despite the currently inadequate treatment options. In the present study, a case of pilomatrix carcinoma of the parotid region with early local recurrence only 2 months after complete excision with negative surgical margins is reported. The local recurrence was treated by excision and radiotherapy. The associated literature is also discussed.