Experience of Two Ventral Foramen Magnum Meningioma

We successfully removed two case ventral foramen magnum meningiomas without any neurologic deterioration. The case was a 73-year-old woman presenting with swallowing difficulty, posterior neck pain, gaiting difficulty, progressive motor, and sensory deficits in all extremities, and intrinsic muscle atrophy in both hands. Magnetic resonance imaging revealed a huge mass, 4×4×4.5cm in size, located in anterior foramen magnum. We removed the mass by performing a partial condylectomy via far lateral transcondylar approach in right side without neurological deficit and postoperative craniovertebral instability. In the second case, a 54-year-old man presented with both upper and lower extremity weakness, accompanied by worsening fine motor control in the right hand and sensory loss in the left leg. The MRI revealed a mass lesion measuring 1.8×2.2×2.0 cm in size in the ventral foramen magnum. The tumor was accessed via a posterior midline suboccipital approach with left side C1, C2 partial laminectomy. The patient did not show any neurologic deterioration or postoperative craniovertebral instability after the operation. There are many factors that we must take into consideration when selecting the optimal approach to a ventral foramen magnum meningioma. We believe that the lateralization of the tumor seen in the MRI is the most important factor.