Intramedullary melanotic schwannoma of the conus medullaris: a case report

Study design: A case of a very rare type of schwannoma is reported. It is the sixth reported case of intramedullary melanotic schwannoma and the only one localized in the conus. Methods: A 56-year-old woman was treated in this department for a C5-C6 spondylodiscitis. After 6 months her arms showed a rapid recovery, but her incomplete flaccid paraplegia remained stable. Magnetic resonance imaging (MRI) with gadolinium enhancement of the lumbar tract revealed an intramedullary lesion at the level of Th12-L1. During surgery, an intramedullary, poorly vascularized, dark gray lesion was detected and was totally removed. One year after surgery, no recurrence was encountered and the patient showed significant improvement. Conclusion: It had previously been hypothesized that intramedullary melanotic schwannomas originate from the rostral components of the neural tube. This case presented a different localization with respect to the previously described cases, all localized in the cervical or high thoracic tracts, and thus uncertainties are raised about the previous hypotheses. Nevertheless, it is agreed that total surgical removal is the best treatment.