Only 2 case reports of bilateral ventrolateral mass at the foremen magnum with surgical management have been reported in the English literature. Liu et al.10 reported a case of bilateral dumbbell C1 neurofibroma and showed excision via a unilateral modified far-lateral approach. Later, Patel et al.11 reported bilateral cervicomedullary junction neurenteric cysts in a child and approached it via a staged far-lateral approach in both sides. However, in our case the pathology was different; it was a dural base tumor with bilateral VA adherence, so the staged-bilateral, far-lateral approach with condyle drilling or a unilateral modified far-lateral approach would have compromised the stability of craniovertebral junction and risked VA injury.
Complete resection rates have varied from 0%–100%, while recurrence rates have varied from 0%–33% in surgical series published in the past 2 decades.12 Factors associated with incomplete resections and recurrences include encasement of the vertebral buy Q-VD(OMe)-OPh ,7 tumor invasiveness (as evident from the extradural component of the tumors) ,3, 13 and 14 and adherences to vital structures, especially in recurrent lesions.4 and 7 At the time of this review, we found only 3 studies specifically addressing the management of FMMs with radiosurgery via the Gamma Knife.12, 15 and 16 Muthukumar et al.15 reported 5 cases of FMMs with tumor reduction in 1 case and no further growth in 4 patients. Likewise, Starke et al.16 reported 5 cases of FMMs with reduction in 1 case and no growth in 4 cases. Zenonos et al.12 published 24 cases of FMMs in which 12 patients had primary symptomatic tumors, 5 had asymptomatic but enlarging primary tumors, and 7 had recurrent or residual tumors after a prior surgery. Ten patients had measurable tumor regression, which was defined as a
n overall volume reduction more than 25%. Eleven patients had no further tumor growth, and 2 patients died as a result of advanced comorbidities. In our case, the patient had been given a choice between GKRS for the residual tumor or staged surgery.Conclusion
We report the first case of incidental bilateral ventrolateral FMM. Resection can be safely and adequately achieved via the unilateral far-lateral approach followed by GKRS or the staged-bilateral, far-lateral approach. Although complete excision of the
tumor is the goal of surgery, it is safer to leave portions of tumor that are adherent to critical structures.Supplementary Data
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Intraoperative features and technique of excision of foramen magnum meningioma. After opening the dura, a right-side tumor was encountered and gently separated from the lower cranial nerves and C1 rootlets. At the end of excision of right-side tumor, a separate capsule was noted. It had a ventrolateral dural origin on the left side.Help with MP4 filesOptionsDownload video (24227 K)