[Pilomatrixoma: a frequent and little known pediatric tumor]

Pilomatrixoma is a benign dermal tumor which is quite frequently observed, but although 50 % of the cases are treated during childhood, it is not well known among paediatricians and paediatric surgeons. Authors report 12 cases localized mainly in the face, neck and upper limbs. Tumors were located in deep dermal layers, they were small, hard and brown or yellow-colored. Microscopic examination revealed basophilic cells which were quite similar to those of basocellular carcinoma, and took origin from hair matrix, and momified or "ghost" cells embedded in a giant cell stroma; lesion was well limited and extended down to subcutaneous fat. In two cases there was a history of infection or insect bites in the site of the lesion and in another one two pilomatrixomas were successively removed from a child whose family had von Recklinghausen's disease. In the majority of patients, preoperative diagnosis was not made, a fact witnessing that this is badly known and justifies this report.