Meningioma, Thoracic intrathecal extramedullary

H&P

• HPI
  • Presented to emergency department
  • Progressive BLE weakness
  • Inability to ambulate
  • No urinary/bowel incontinence
• PE:
  • RLE 4/5
  • LLE 2-3/5
  • Decreased sensation from approximately T9 down
• Workup:
  • Thoracic spine MRI with and without contrast

Imaging

Thoracic spine MRI with and without contrast

There is a homogeneously enhancing intradural extramedullary lesion at the T8-T9 level (localized caudally from C1 on scout MRI). The mass causes significant mass effect, displacing the spinal cord to the right. A visible dural attachment (red arrow) is noted, highly suggestive of a spinal meningioma."

Differential Diagnosis

• Meningioma
• Schwannoma
• Neurofibroma
• Ependymoma
• Metastatic lesion

Surgical Intervention

• Neuro-monitoring
  • SSEP
  • MEP
  • EMG
  • D-wave
• X-ray machine
• Ultrasound
• Microscope
• Prone
• Superman position
• Free-hanging abdomen
  • Reduces venous pressure and epidural bleeding
• Localization with X-ray
• Midline incision on T8-T9
• T8 and T9 laminectomy
• Confirmation of tumor location by ultrasound
• Dural incision, slightly off midline to the left
• Dura tented with 4-0 Nurolon
• Open arachnoid
• Separate tumor from spinal cord and T8 nerve root
• En bloc resection
• Coagulation of tumor's dural attachment
• Water-tight dural closure (6-0 Prolene)
• Valsalva
• Blood patch
• Tisseel
• Routine closure
• Stable neuro-monitoring throughout whole case

Intra-operative Imaging

Intraoperative fluoroscopy was used for level localization.
Two separate shots were taken (upper two), counting cranially from the sacrum/L5.
NB: this patient has sacralization of L5 and the spinal needle is located at L1.

Following the laminectomy, intraoperative ultrasound was utilized to localize the tumor and define its cranial and caudal extents prior to the durotomy.

Under microscopic visualization, the surgical field was oriented with the cranial direction to the left. The tumor was observed to be ventral and left-lateral to the spinal cord. With the patient in the prone position and the operator standing on the patient’s left, the lesion was identified displacing the cord dorsoposteriorly and toward the right.

The tumor was removed on bloc. All the nerves and vessels were kept intact. The dural attachment was coagulated.

Tumor specimen.

Post-op Course

• Admitted to regular ward
• Flat for 48 hours
• No new neurological deficits
• Improved BLE strength
• Out of bed after 48 hours
• Ambulating with physical therapy
• No CSF leak or orthostatic headache
• Discharged to a rehabilitation center on POD4

Pathology

Meningothelial meningioma, CNS WHO grade 1.
The black arrows are pointing at the psammoma bodies.

Discussion

• Meningioma is the most common intradural extramedullary tumor.
• Typical MRI findings⇧:
  • T2 hypointense
  • Homogenous enhancement
  • Dural tail
• Gross total resection achieves > 95% cure rate for grade 1 meningiomas.