Intraspinal primary melanoma of intermediate grade : a case report and literature review

The incidence of primary central nervous system (CNS) melanocytic neoplasms is relatively low compared to that of systemic melanocytic neoplasms. This type of tumor is rare, and its clinical, radiological, and histopathological characterization is therefore poor, presenting a challenge for its diagnosis and treatment. Amelanotic melanoma-particularly intraspinal primary melanoma of intermediate grade-is an especially rare subtype. Here, we report a case of intraspinal primary melanoma of intermediate grade. Preoperative assessment revealed a neurogenic tumor for which the patient underwent resection. Pathologic analysis determined that the tumor was a melanoma of intermediate grade. Upon admission to the hospital, neurological examination of the patient revealed hypoesthesia below the umbilical level and progressive weakness (grade IV) of the right lower limb. The patient’s familial history was negative, with no neurocutaneous system disorders occurring in first-degree relatives. The tumor was completely resected using a standard posterior midline approach. The patient was discharged after surgery with improved motor capacity, and a follow-up MRI scan revealed no recurrence after two years. Cases of intraspinal primary melanoma of intermediate grade are very rare; although this case is diagnosed as intermediate grade, it may behave aggressively. Complete surgical resection is curative for most cases. Radiation therapy is important to prevent recurrence, especially in cases of incomplete surgical resection.