History: A 43-year-old woman initially presented with left-sided hearing loss in 2007 (initial diagnosis withheld) now presents with progressive gait instability and new left arm pain and numbness.
An MRI scan of the head was performed. In order: axial T2-weighted, axial T2-weighted fluid-attenuated inversion-recovery (FLAIR), axial T1-weighted postcontrast, coronal T1-weighted postcontrast, axial diffusion-weighted (DWI), and axial apparent diffusion coefficient (ADC) images of the brain.
An MRI scan of the cervical spine also was performed. Sagittal and coronal T2-weighted, sagittal T1-weighted precontrast, sagittal T1-weighted postcontrast, and axial T1-weighted postcontrast images are shown below.
Head MRI: There are multiple heterogeneously enhancing masses involving the right Meckel\’s cave, right cerebellopontine/cerebellomedullary angle, left cerebellopontine angle and internal auditory canal extending to the fundus and the cochlear aperture, and along the left cisternal trigeminal nerve into Meckel\’s cave. These are most consistent with multiple schwannomas. There is stable mass effect on the right cerebellum and brainstem, compression of the fourth ventricle, and prominence of the ventricular system. There is no acute hemorrhage, infarct, or pathologic parenchymal enhancement.
C-spine MRI: Multiple nerve sheath tumors are seen in the cervical spine and neck, including along the right C2 and left C5 nerve roots, consistent with schwannomas. Intraspinal lesions at C3-4 cause mass effect and distortion of the cord.
- Neurofibromatosis 2
- Multiple meningiomas
- Tuberous sclerosis
- Neurofibromatosis 1
- von Hippel-Lindau syndrome
- von Hippel-Lindau综合征
Diagnosis: Neurofibromatosis 2
Genetic testing is used for definitive diagnosis. However, bilateral vestibular schwannomas are considered diagnostic. Additionally, a combination of unilateral vestibular schwannomas with meningioma and other associated CNS tumors in the setting of a first-degree relative also can be used to make a clinical diagnosis.
Imaging features 影像表现
Imaging is crucial for understanding the exact malformations present in each individual and for presurgical planning.
- Vestibular schwannomas (approximately 96% of patients):
Vestibular schwannomas (CN VIII) usually occur in the internal auditory canal or porus acusticus, and 90% of patients develop bilateral vestibular schwannomas.
On CT, they are hypodense to isodense, may calcify, and may enlarge the bony internal auditory canal.
On MRI, they are hypointense on T1, hyperintense on T2, and display avid contrast enhancement.
Larger lesions are often more heterogeneous with possible hemorrhage.
Schwannomas involving the fifth to ninth and 12th nerves also are often seen, with variable appearance, including presenting as nodular masses, sometimes with enlargement of skull base foramina.
- Meningiomas (approximately 58% of patients):
There can be multiple meningiomas that can range in size and that occur in an early age.
They appear as dural-based extra-axial lesions, isointense to gray matter on T1- and T2-weighted imaging with avid contrast enhancement.
- Spinal tumors (approximately 55% of patients):
Includes intramedullary ependymomas, schwannomas, and meningiomas, which can be seen throughout the spine.
Can be associated with a syrinx.
Transcortical and leptomeningeal meningovascular proliferation is seen with focal calcifications and is associated with headaches and seizures.
Nodular cortical or subcortical masses extending to overlying leptomeninges in a plaque-like appearance can be seen anywhere in the brain.
- Peripheral schwannomas:
Arise from dorsal nerve roots with some extradural extensions (dumbbell morphology).
Appear isointense to skeletal muscle on T1 and hyperintense on T2, with avid contrast enhancement.