Neurofibroma and Meningioma within a Single Dumbbell-Shaped Tumor at the Same Cervical Level without Neurofibromatosis: A Case Report and Literature Review.

Abstract

Cases of multiple intracranial tumors are common; however, cases of multiple intraspinal tumors are rare. Except for cases of neurofibromatosis, it is very rare for tumors of different pathological types to exist concurrently at the same spinal level. Only 9 cases have been reported to date, with meningioma found with schwannoma in 7 cases and with neurofibroma in 2 cases. We have reported another rare case in which neurofibroma and meningioma were identified within a single dumbbell-shaped tumor at the same cervical level without neurofibromatosis. The preoperative magnetic resonance imaging findings indicated a single extra- and intradural extramedullary dumbbell-shaped neurogenic tumor on the left ventral side of the cervical spine. Intraoperatively, we found that the mass consisted of 2 pathologically different tumors. The results of surgical resection were mostly satisfactory. To the best of our knowledge, the present case is the first reported case of intradural neurofibroma (not meningioma) and extradural meningioma growing mixed together at the same spinal level without neurofibromatosis. The precise mechanism underlying the formation of the tumor is unknown, and multidirectional differentiation of a common progenitor cell is one possibility. Intra- and extradural exploration and component biopsies are useful for treatment planning, especially when the magnetic resonance imaging is not sufficiently sensitive for the diagnosis of coexisting tumor types.