Malherbe’s Masquerade

Abstract

Introduction: Pilomatricoma, also known as calcifying epithelioma of Malherbe, was first described by Malherbe and Chenantais in 1880. It was described as a benign cutaneous tumour arising from the sebaceous glands. In 1961, its classical histopathological characteristics of epithelial cells and shadow cells were documented and hence, it was renamed as Pilomatricoma to be correct etymologically. Case Report: A 47 year old male was referred to the cytology lab from the general surgery outpatient department for a fine needle aspiration with a history of a swelling on the right side of the neck since 1 year which was gradually progressive in size, no pain/discharge. A clinical diagnosis of? sebaceous cyst was provided.On examination, solitary swelling on the right side of the neck, 5 cm below the angle of the mandible, measuring 1.5x1 cm, firm in consistency, well defined with a smooth surface and mild erythema. Skin over the swelling -pinchable. Fine needle aspiration was performed and on microscopy, the smears obtained were highly cellular and showed tight clusters of basaloid cells and few were singly dispersed. This was admixed with keratin flakes and few shadow cells, background also showed occasional multinucleate giant cells. A diagnosis of Benign adnexal tumour morphology favouring pilomatricoma was given. Following the Fine needle Aspiration cytology report, he underwent an excision biopsy. Grossly -skin covered nodular tissue bit, cut surface -grey white areas with specs of calcification. Microscopically, an encapsulated lesion composed of basaloid cells undergoing abrupt transition to the formation of shadow cells with central clearing, mixed inflammatory infiltrate and foreign body giant cells.A diagnosis of Pilomatricoma was made. Conclusion: Pilomatricoma (PMC) is a relatively uncommon benign skin neoplasm arising from the skin adnexa. Although there has been a gradual increase in the understanding of its clinical presentation and morphological features however, difficulties still persist in making a cytologic diagnosis. The purpose of this case report is to create awareness about the cytological features of pilomatricoma.