Complicated Giant Pilomatrixoma of the Parotid Region

Abstract

Objective: Pilomatrixoma (calcifying epithelioma of Malherbe) is a benign soft tissue tumour arising from dermis or subcutaneous tissue which should be considered in differential diagnosis of preauricular lesions especially when skin fixation is present.

Case report: Twenty-three year old male referred to our clinic with complaint of left preauricular swelling over 18 months which enlarged and became painful in the last 2 months. Because the lesion showed signs of infection, surgery was planned after medical therapy was completed. FNAB suggest pleomorphic adenoma as preliminary diagnosis. US or MRI showed no specific feature.

Treatment and prognosis: Total excision, superficial parotidectomy with facial nerve sparing was performed after regression of infectious signs. Postoperatively no recurrence was detected.

Conclusion: Pilomatrixomas are benign tumours but have diagnostic difficulties according to clinical and cytologic findings. This rare lesion should be kept in mind to avoid misdiagnosis as malign parotid tumours, particularly in the presence of skin change.

Keywords: Complication; Giant; Parotid region; Pilomatrixoma; Skin neoplasm.

Fig. 1

Preoperative clinical view of patient from left and front aspects. Fistulisation and hyperemia was seen in overlying skin

Fig. 2

Coronal MR imaging. 4 × 3 cm mass with partial contrast enhancement anterior to left parotid gland

Fig. 3

Tissue specimen removed preoperatively

Fig. 4

A Tumour which is surrounded by fibrous tissue adjacent to the parotid gland (H and E, original magnification ×40). B Tumour showing irregular blands of epithelial cells composed of basophilic cells and shadow cells (H and E, original magnification ×100)

Fig. 5

Front and left lateral view of the patient at postoperative seventh month