A nevoid plaque with histological changes of trichoepithelioma and cylindroma in Brooke-Spiegler syndrome. An immunohistochemical study with cytokeratins.

Brooke-Spiegler syndrome is characterized by the development of multiple trichoepitheliomas and cylindromas. In addition, multiple spiradenomas have been observed in this autosomal-dominant inherited disease. We report a 53-year-old woman with multiple cylindromas on the head and neck and multiple trichoepitheliomas on the face. Additionally, she had had since birth a plaque on the right side of her neck containing two nodules with features of both cylindroma and trichoepithelioma. Immunohistochemical investigations revealed in the basaloid cells of trichoepithelioma an expression of CK 5/6, CK 14, CK 17, CK 19 and vimentin. The cells of the cylindroma lacked vimentin but expressed additionally CK 7, CK 8 and CK 18. The occurrence of cylindroma and trichoepithelioma in a single nevoid plaque from a patient with Brooke-Spiegler syndrome implies an alteration in the stem cells of the folliculosebaceous-apocrine unit and could be characteristic of the disorder.