Intramedullary tumors are a subgroup of spinal tumors and are associated with high morbidity and mortality. The estimated incidence of spinal tumors in general is 0.74 to 1.6 per 100 000 persons per year, with intramedullary tumors making up 10% to 30% of the total. The diagnosis is often delayed because of the insidious onset of symptoms, which are often nonspecific at first. This review is based on pertinent publications about intramedullary tumors that were retrieved by a selective search in the PubMed database. Intramedullary tumors often cause diffuse neurologic symptoms of gradually increasing severity, progressing, in advanced cases, to a complete spinal cord transection syndrome. Magnetic resonance imaging of the spine without and with intravenous contrast is the standard diagnostic technique. The histopathological origin of most intramedullary tumors is from glial cells, but other types of intramedullary tumor exist as well. The primary treatment of all intramedullary tumors is surgical resection. 9% to 34% of patients may experience a worse neurological deficit after surgery than before, but such problems resolve completely in 25% to 41% of cases. The extent of resection is the main factor affecting the risk of tumor recurrence and progression. The extent of resection also determines the possible indication for adjuvant treatment, which is needed, in particular, for high-grade and subtotally resected tumors, and for those that display progression. The treatment of intramedullary tumors is based on case series, retrospective analyses, and case reports, as randomized trials are lacking. Patients with intramedullary tumors should be cared for, as much as possible, in the setting of prospective, uniform studies of their spontaneous course and the outcomes after treatment. This will yield better evidence on the treatment of these tumors in the future.
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