A Case of Trichogerminoma With Pilomatrical Differentiation and a Unique Immunohistochemical Profile.

Trichogerminomas are rare adnexal neoplasms first described by Sau et al in 1992. Including the initial report, 20 cases have been reported, all with similar histological features, namely tumor nodules composed of basaloid cells that form densely packed, round nests or "cell balls" and which demonstrate variable degrees of pilosebaceous differentiation. In this study, the authors report a case of a trichogerminoma with pilomatrical differentiation and a unique immunohistochemical profile.