A case of perforating pilomatricoma mimicking intradermal nevus on the scalp = A case of perforating pilomatricoma mimicking intradermal nevus on the scalp

다국어 초록 (Multilingual Abstract)

Pilomatricoma (calcifying epithelioma of Malherbe) is a relatively common benign skin tumor of childhood arising from the hair follicle matrix. There are several clinical variants of pilomatricoma, including, lymphangiectatic, anetodermic, pseudo-bullous and perforating form. Perforating pilomatricoma is a rare clinical subtype, and typically presents as an exophytic, crusted or ulcerated, erythematous to flesh-colored nodule on the head and neck. Histopathologically, it shows islands of cells composed of peripheral nucleated basaloid cells and central enucleated shadow cells in the dermis. Differential diagnosis includes trichoepithelioma, trichilemmal cyst, and intradermal nevus. The treatment of choice for pilomatricoma is surgical excision, and the recurrence rate is low. A 10-year old boy presented with 2-month history of a 0.6 x 0.5 cm sized, skin-colored to erythematous, protruding mass, without ulcer and crust, on the scalp. Excisional biopsy was done under the impression of intradermal nevus and histopathologic findings from the excised specimen showed a well-circumscribed tumor composed of enucleated eosinophlic cells surrounded by basaloid cells in the papillary dermis. The patient was diagnosed with perforating pilomatricoma. Herein, we report a case of perforating pilomatricoma mimiking intradermal nevus.