A patient with pilomatricoma in the parotid region: case report and review of the literature.

Pilomatricoma is a benign skin tumor originating from the matrix cells of the hair follicles. Sometimes, its diagnosis can be difficult, especially in the preauricular region, where in the differential diagnosis, in addition to other dermal and subcutaneous masses, primary and secondary parotid gland tumor lesions must be also considered. A 34-year-old female was referred to our Institution with a right preauricular swelling over 12 months, which enlarged in the last two months. The ultrasonography confirms the origin of the tumoral mass in the skin of the preauricular region and not from the superficial lobe of the right parotid gland. The patient underwent complete tumor excision and the histopathology and immunohistochemical exams confirmed the diagnosis of a conventional pilomatricoma evolving to a late regressive lesion. She was discharged considered as cured and no recurrences were reported within a period of eight months of follow-up. This is the first reported case in the last 30 years, in this location, in the Department of Oral and Maxillofacial Surgery our Institution. Regarding the rarity of these tumors, especially in this location, we must keep in mind to consider a broader differential diagnosis that includes both tumoral and non-tumoral skin lesion and also parotid gland lesions.