Intramedullary melanotic schwannoma: Case report and review of the literature

BACKGROUND: Intramedullary melanotic schwannomas are very rare. Only seven cases have been previously reported. This is the first reported case of such a tumor presenting with intratumoral hemorrhage closely mimicking a hemorrhagic ependymoma. CASE DESCRIPTION: A 23-year-old female patient presented with progressive right lower extremity pain and numbness for 3 months and this was followed by acute paraparesis and urinary incontinence. Physical examination revealed sensory and motor dysfunction below T4 level. Magnetic resonance imaging of her spine showed a heterogeneous signal lesion occupying the intramedullary space with small foci of hyperintensity on T1WI and hypointensity on T2WI at the T4-5 level. She underwent emergent surgical decompression and microsurgical excision of the tumor. A histopathological diagnosis of melanotic schwannoma was made. Postoperative neurological recovery revealed progressive improvement in her examination findings. CONCLUSION: Among spinal cord neoplasms, melanotic schwannomas are extremely rare tumors. The similar source of Schwann cells and melanocytes, the neuroectoderm, has been suggested to be the origin of melanotic schwannomas. Intramedullary melanotic schwannomas presenting with hemorrhage tend to be mistaken with ependymoma, which by far is the most common spinal tumor to present with hemorrhage. Total surgical excision if safely possible is currently considered the ideal treatment of choice.