Mirror meningioma at foramen magnum: Enigma in management of a very rare case

BACKGROUND: We report a very rare case of bilateral foramen magnum mirror meningioma and discuss difficulties in managing the surgical challenge. To the best of our knowledge, mirror foramen magnum meningioma (FMM) has been reported only once in literature. FMMs are rare and also a great challenge for neurosurgeons due to the complex anatomy of this area. The purpose of this article is to illustrate the rare occurrence of bilateral meningioma in the foramen magnum and the difficulties in managing the surgical challenge. CASE DESCRIPTION: A case of a 45-year-old female presented with neck pain, paresthesia in all four limbs, and difficulty in walking for 1 year duration. Magnetic resonance imaging revealed well-defined lobulated dural based mass lesion at foramen magnum on both sides. The left vertebral artery (VA) was encased within the lesion while the right VA was seen abutting it. Tumor was resected gross totally on the right side. However, during the resection of the medial part of the left side tumor, it was found to be adhered to the VA. Since the mass was adherent to the left VA, subtotal resection was done. CONCLUSION: There is no single best surgical approach for FMMs and the optimal approach should be defined according to the localization and the extent of the tumor to minimize the extent of resultant morbidity. Although complete excision of the tumor is the aim of surgery, it is safer to leave portions of tumor that is adherent to critical structures which can be managed by Gamma Knife radiosurgery.