Laboratory Studies
The following studies are not diagnostic of tumor pathology and are reserved as part of preoperative planning:
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CBC count
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Sequential Multiple Analysis-7
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Prothrombin time/activated partial thromboplastin time
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Sequential Multiple Analysis-12 (optional)
Imaging Studies
MRI
MRI is the most accurate and noninvasive technique for imaging the spine and is the imaging modality of choice. Gadolinium (contrast) requires evaluation of kidney function because cases of malignant fibrosis have been reported. General findings include enlargement of the spinal cord and syringomyelia or cystic cavity associated within the lesion. (See the images below.)
Ependymoma findings are as follows:
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T1-weighted images: Isointense signal with spinal cord
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T2-weighted images: Hyperintense signal
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Strong homogeneous enhancement with contrast
Astrocytoma findings are as follows:
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T1-weighted images: Isointense or hypointense signal with spinal cord
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T2-weighted images: Hyperintense signal
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Cyst formation
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Heterogeneous enhancement with contrast
Hemangioblastoma findings are as follows:
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T1-weighted images: Isointense signal to spinal cord
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T2-weighted images: Hyperintense signal
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Cystic with tumor nodule (50-70%)
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Enhances strongly with contrast
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Extramedullary extension in 15%
This T1-weighted sagittal MRI is from a 19-year-old man with 4-month history of progressive motor loss and an inability to ambulate. He underwent spinal biopsy that confirmed an intramedullary glioblastoma.
This T2-weighted MRI is from a 19-year-old man with 4-month history of progressive motor loss and an inability to ambulate. He underwent spinal biopsy that confirmed an intramedullary glioblastoma.
Plain radiography
Plain radiography is not accurate for diagnosis. Abnormalities are identified in 20% of patients. Possible findings include the following:
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Scalloping of the vertebral bodies on lateral radiographs
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Widening of interpedicular distance on anteroposterior radiographs
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Scoliosis in children that results from neuromuscular impairment
Myelography
Myelography is not an optimal modality because it is invasive and can alter spinal fluid dynamics, causing neurologic worsening. Findings may include the following:
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Nonspecific spinal canal and spinal cord widening
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Multisegmental involvement
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Block of contrast dye
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Conus region lesions, possible meniscus around the tumor
CT scan
CT findings include the following:
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Nonspecific spinal canal and spinal cord widening
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Scalloping of vertebral bodies
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Possible intraparenchymal syringomyelia
Spinal arteriography
Spinal arteriography is beneficial only if a hemangioblastoma is suggested as part of the differential diagnosis. Hemangioblastoma arteriography findings include a vascular blush with a prominent draining vein.
Other Tests
Baseline urodynamics
Findings may assist in diagnosing abnormal bladder function.
Neurophysiologic testing (EMG/NCS/SSEP)
Findings may quantify degree of neurologic injury from tumor.
Diagnostic Procedures
Lumbar puncture is not indicated unless the patient is being evaluated for drop metastasis or leptomeningeal spread of intracranial disease (as in cranial ependymomas). In addition, lumbar puncture may be useful to differentiate from infectious or inflammatory myelitis (multiple sclerosis). However, clinical presentation and imaging studies can typically exclude these etiologies.
Neurologic deterioration can be precipitated after lumbar puncture if a complete myelographic block is present from changes in the lesion and position of the neoplasm.
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This T1-weighted sagittal MRI is from a 19-year-old man with 4-month history of progressive motor loss and an inability to ambulate. He underwent spinal biopsy that confirmed an intramedullary glioblastoma.
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This T2-weighted MRI is from a 19-year-old man with 4-month history of progressive motor loss and an inability to ambulate. He underwent spinal biopsy that confirmed an intramedullary glioblastoma.
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This 28-year-old man presented with progressive tetraplegia. T2-weighted sagittal MRI illustrates an intramedullary ependymoma, confirmed with pathologic evaluation. Note the cysts at the cranial (top) and caudal (bottom) of the tumor.
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Postoperative axial MRI (patient from Image 3) at distal region of resection. A complete or gross total resection was obtained and confirmed with postoperative MRI. Note the cyst cavity has collapsed and the spinal cord is significantly atrophied. Despite the small size of the spinal cord, the patient experienced significant improvement in his neurologic function postoperatively.
