Rare presentation of malignant melanoma as qauda equna syndrome from intradural extramedullary metastasis

Abstract

Background: The incidence of metastatic melanoma (MM) has been steadily rising, and it is the third most common metastatic lesion to the central nervous system. Spinal intradural extramedullary MM is rare, and it is associated with coexisting or antecedent brain metastasis. A 66-year-old patient presented to us with a seizure, malaise, low back pain, progressive weakness of both lower limbs, and bladder dysfunction. She had a known history of MM of the brain, which was diagnosed just 5 months before the current presentation. 5 months ago, she was admitted to the Neurosurgery clinic and underwent an excision of one of three metastases in the brain. The histopathological findings were consistent with malignant melanoma that was confirmed with immunohistochemistry examination (positive for S-100, Melan-A, and HMB-45). The patient underwent an extensive magnetic resonance imaging scan of the brain and lumbosacral region that suggested T1 hyperintense, T2 hypointense, intradural extramedullary altered signal intensity lesions at the cauda equina region as well as widespread leptomeningeal disease. Here, we are discussing an unusual case with a comprehensive review regarding the pathogenesis, diagnosis, and prognosis of the tumor. Conclusion: Brain metastasis from melanoma is associated with a poor prognosis, with an average survival of only 4–6 months after diagnosis. Leptomeningeal metastasis and extramedullary metastatic involvement indicate the terminal stage of the disease. Although the overall prognosis remains unfavorable, emerging mechanism-based therapies have improved survival and quality of life for some patients. Nevertheless, early diagnosis of melanoma remains the key factor in improving patient outcomes.