A patient with ulcerated calcifying epithelioma of Malherbe in the pinna: case report

Abstract

Introduction: Although pilomatrixomas are frequently encountered by dermatologists and pathologists in the differential diagnosis of head and neck lesions, this is not usually the case among head and neck surgeons. A pilomatrixoma (calcifying epithelioma of Malherbe) is a benign tumour of the hair matrix cells. Histologically it is characterised by the presence of ghost cells, basophilic cells and foreign body cells. It may sometimes be difficult to histologically distinguish it from its malignant counterpart, the pilomatrix carcinoma. We report an interesting case of an ulcerated pilomatrixoma of the pinna in a middle-aged Caucasian female.

Case presentation: A 46-year-old Caucasian female presented with a one-month history of tender brownish lump on the pinna. Initially it was thought to represent a pyogenic granuloma. The lesion was treated by wide circular excision. Histopathological evaluation reported a benign calcifying epithelioma of Malherbe.

Conclusion: A search of the world's literature has led us to believe that this is a rare case of a calcifying epithelioma of Malherbe of the pinna. The rapid growth and ulcerative nature of this tumour makes this case even more unique.

Figure 1

Clinical photograph of the pinna showing an ulcerated lesion.

Figure 2

H&E stained section taken with low-power objective. This view shows the lobular architecture of the tumour and demonstrates the typical biphasic population of darkly staining basaloid cells (left) and the larger more eosinophilic ghost keratinocytes (right)

Figure 3

H& E stained section taken with a medium power objective. Squamous epithelium is shown on the right side adjacent to eosinophilic keratinous debris with visible ghost outline of tumour cells and calcification towards the centre. The granular layer is not in evidence and there is abrupt keratinisation in keeping with the predominantly pilar keratinisation seen in pilomatricoma.

Figure 4

H&E stained section taken with a medium power objective. This shows maturation in pilomatricoma. The basaloid cells shown in the bottom right of the picture gradually become enlarged and more eosinophilic, the nuclei become pyknotic and eventually form the ghost cells characteristic of this tumour. There is foreign body reaction top left which is often seen in association with pilomatricoma