Primary cerebellar tuberculoma in Arnold-Chiari malformation mimicking posterior cranial fossa tumor: the first report

Abstract

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: Arnold-Chiari malformation; cerebellar tuberculoma; cranial fossa tumor.

Figure 1

Brain magnetic resonance imaging. 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.

Figure 2

Cervical spine magnetic resonance imaging. Cervical cord has a normal diameter and signal without evidence for compression. Cervical vertebrae have normal height without fractures or pathological lesions. Cervical canal has a normal diameter without any congenital or acquired stenosis. The alignment of the cervical spine is normal without any evidence for disc herniation. Tonsillar herniation to the cervical spine is seen.

Figure 3

Spiral chest computed tomography. Pulmonary parenchyma and vessels are normal. There is no nodule or occupied lesion in the parenchyma. Mediastinum and pulmonary hila are normal. No pleural lesion or pleural effusion is seen. Pericardium is normal. Mediastinal vessels do not show any pathology. Lungs are relatively hyperinflated.