Calcifying epithelioma (pilomatrixoma) of the head and neck: analysis of 37 cases

Objective: To review all cases of pilomatrixoma (calcifying epithelioma) of the head and neck published in Japanese dental journals 1977–1994. Design: Retrospective review. Setting: University hospital, Japan. Subjects: 37 Patients with 38 tumours, mean age 23 years, female: male ratio 2.4:1. Interventions: Enucleation alone (n=29, 78%), excision including covering skin (n=7, 19%), or excision including superficial lobe of parotid (n=1, 3%). Main outcome measure: Presentation, site, recurrence, and histological features. Results: Two patients had multiple tumours (5%). Most of the tumours were firm nodules covered with normal skin varying in size from 5 to 30 mm. The most common site was the preauricular region; 22 (58%) were in the anterior part. The follow up period ranged from 7 to 43 months during which there was only one recurrence. Tumours were encapsulated and solid composed of either shadow and basophilic cells or shadow cells alone, and the stroma contained varying amounts of calcification, ossification, and keratinization. Conclusions: The diagnosis should be suspected when the mass is adherent to the skin but not fixed to the underlying tissue. It is difficult to distinguish between benign and malignant tumours by imaging methods alone, so the recommended treatment must be complete excision including adherent skin.