Intracranial posterior fossa proliferating trichilemmal tumor: first case report.

Proliferating trichilemmal tumors (PTT) are rare benign lesions that predominantly occur in elderly women and usually affect the scalp. They originate from the outer root sheath of hair shafts and have trichilemmal differentiation on histopathological examination. Compared to trichilemmal cysts, PTTs show increased cell proliferation and variable cytological atypia. We report the first case of a patient with an intracranial PTT in the posterior fossa. The clinicoradiological presentation and surgical management of the patient as well as the possible pathogenesis of this tumor are discussed.