Introduction: Primary malignant melanoma accounts for approximately 1% of all CNS melanomas, and only 60 cases have been reported in the literature, with different locations including intramedullary, intradural, and extradural lesions.

Case report: A 41 year-old man brought to ER with a severe back pain, progressive paraparesis, saddle anesthesia and urinary retention. MRI of thoracic and lumbar spine showed an intradural mass lesion from T10 to L3, significant rostral displacement of the conus, hyperintense heterogenous on T1, homogeneous hypointense on T2, and mild heterogeneous enhancement. with contrast. An urgent lumbar laminectomy T10-L3 was performed. A greyish dark encapsulated tumor mass was found in the intradural space surrounding the lumbar roots from both sides. A subtotal resection of the tumor was performed with decompression of the conus medullaris and lower lumbar roots. Histological analysis revealed cells with big nuclei and prominent nucleoli, extra e intracelullar pigment, strong immunohistochemical reactions for Melan A and HMB45. On posoperative careful physical and radiological examination of the squamous mucosa, eyes, and skin, as well as of other CNS was negative for melanoma and whole-body PET scan revealed an intense 18F-FDG uptake at the residual mass site, without abnormal uptake at other sites, excluding metastatic melanoma. Postoperatively patient was able to walk with assistance, with partial reversion of the saddle anesthesia and need of intermittent urinary catheterization, Patient received radiotherapy and chemotherapy cycles with Ipilimumab. Four months after discharge, patient suffered of sudden neurological deterioration due a hemorrhagic cerebellar metastasis with a fatal outcome.