Primary Cerebellar Tuberculoma in Arnold-Chiari Malformation Mimicking Posterior Cranial Fossa Tumor: The First Report

摘要

Chiari malformations are a congenital heterogeneous group of disorders characterized by anatomic anomalies of the cerebellum, brain stem, and craniocervical junction associated with downward displacement of the cerebellum, alone or with lower medulla, into the cervical spine canal. The patient was a 23-year-old woman, a known case of Arnold-Chiari malformation with peripheral neuropathy and muscular atrophy, who presented with headache, drowsiness, decreased vision, and severe gait dysfunction lasting for several years. Brain magnetic resonance imaging confirmed a hypointense signal mass in the left hemisphere of the cerebellum causing mass effects on the fourth ventricle, which shifted it, accompanied with dilation of third and lateral ventricles. Keywords: cerebellar tuberculoma, Arnold-Chiari malformation, cranial fossa tumor Chiari malformations are a congenital heterogeneous group of disorders characterized by anatomic anomalies of the cerebellum, brain stem, and craniocervical junction associated with downward displacement of the cerebellum, alone or with lower medulla, into the cervical spine canal. 1 These disorders are first described by John Cleland in 1883 2 3 and were classified later by Hans Chiari in 1891 into four groups. 1 4 Arnold-Chiari malformation, or Chiari II malformation, is characterized by downward displacement of the cerebellar vermis and tonsils, a spinal myelomeningocele, and a brain stem malformation with beaked midbrain in neuroimaging. We report an unusual case of Arnold-Chiari malformation with primary cerebellar tuberculoma mimicking posterior cranial fossa tumors. To our knowledge, this is the first report of primary cerebellar tuberculoma in a patient with Arnold-Chiari malformation.