Pilomatrical carcinoma – a case report and review of the literature

Abstract

We report a case of an 85-year-old man, who presented with a polypoid skin tumor in the left lumbal region. Histology revealed a malignant tumor composed predominantly of pleomorphic basaloid cell population with a high mitotic and proliferative activity. This cellular component was admixed with aggregates of anuclear cells with eosinophilic cytoplasm reminiscent of „shadow” cells seen in pilomatrixoma, as well as with whorls of keratin material reminiscent of squamoid pearls. Immunohistochemically, the basaloid tumor part was positive for CD10, p120catenin and CD138 and very sporadically positive for cytokeratin 19 and BerEP4. Cytokeratin 20 was negative and epithelial membrane antigen labelled only eosinophilic squamoid structures. In some areas, numerous interspersed dentritic melanocytes strongly immunoreactive for S-100 protein were arranged singly and in larger expansile nests within basaloid tumor mass. Histopathology and immunoprofile of lesion favored a diagnosis of pilomatrical carcinoma with intratumorous melanocytic proliferation. To the best of our knowledge, only a few such cases have been described untill now.

Keywords

• Pilomatrical carcinoma
• Pilomatrixoma
• Adnexal tumors