Intramedullary Tumors (Tumors Within the Spinal Cord)
Intramedullary tumors are rare tumors that arise within the spinal cord tissue and make up a small fraction of all spinal tumors. In adults the most common types are ependymoma and astrocytoma. They cause slowly progressive pain, weakness and sensory loss; the mainstay of treatment is microsurgical resection.
Última actualización: 2026-06-06
Definition
Intramedullary tumors are primary tumors located within the parenchyma of the spinal cord. Spinal tumors are classified by location as extradural (outside the dura), intradural-extramedullary (inside the dura but outside the cord) and intramedullary (within the cord); the intramedullary group is the least common (about 4-10% of all spinal tumors). Because they involve the cord's own tissue and are intimately related to critical neural structures, their surgery is among the most technically demanding spinal operations. They are proportionally more frequent in children than in adults.
Tumor Types
In adults the most common type is ependymoma; it usually lies in the midline, is well-circumscribed and often has a cystic component, making it more amenable to complete (total) resection. The second most common is astrocytoma; it grows infiltratively with indistinct margins and total resection is often not possible (it is more common in children). Hemangioblastoma is a benign, vascular tumor, some cases of which are associated with von Hippel-Lindau disease. Less commonly, ganglioglioma, lipoma, epidermoid/dermoid cysts, lymphoma and intramedullary metastases may occur.
Symptoms
Symptoms of intramedullary tumors usually begin slowly and insidiously, with months to years before diagnosis. Pain is the most frequent first complaint; local pain at the tumor level, a night-time pattern and dural stretching are typical, and central (neuropathic) pain may occur. Motor findings begin with weakness, loss of fine dexterity and difficulty walking, progressing to paresis/plegia and spasticity. Sensory findings include selective loss of pain and temperature sensation (dissociated anesthesia) and, with posterior column involvement, loss of position and vibration sense with ataxia. Advanced cases develop bladder-bowel dysfunction.
Diagnosis
Contrast-enhanced magnetic resonance imaging (MRI) is the gold standard; it shows the tumor level, its extent within the cord, any cystic component, associated syringomyelia and the pattern of contrast enhancement. These features help distinguish ependymoma from astrocytoma, but definitive diagnosis is made by histopathology. Spinal angiography may be useful for a markedly vascular hemangioblastoma. When von Hippel-Lindau is suspected, neuraxis-wide imaging and genetic evaluation are performed.
Treatment Options
The mainstay of treatment is microsurgery that achieves the widest safe resection while preserving neurological function. The operation is performed with an operating microscope, ultrasonic aspirator and intraoperative neurophysiological monitoring (motor and somatosensory evoked potentials). Total resection is often possible for well-circumscribed ependymoma and hemangioblastoma; for infiltrative astrocytoma the aim is safe debulking and diagnosis. Radiotherapy, and chemotherapy in selected cases, are considered for high-grade, subtotally resected or recurrent tumors. Some small, asymptomatic lesions (especially the multiple hemangioblastomas of VHL) may be observed.
Postoperative Course
In the early postoperative period the neurological status is closely monitored; because transient sensory disturbance and weakness can occur, early rehabilitation is important. Physical therapy and bladder management as needed support recovery. Additional treatment (radiotherapy) is planned according to the histopathology. Regular MRI follow-up is performed to watch for recurrence and growth.
Prognosis
Prognosis depends on tumor type, grade and preoperative neurological status. Outcomes are good for totally resected benign ependymoma and hemangioblastoma, with long-term control achievable. Prognosis is more limited for infiltrative astrocytoma and high-grade tumors. Good preoperative neurological status is one of the strongest predictors of postoperative functional outcome, which is why early diagnosis matters. Outcomes vary individually.
Referencias
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:984-988.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011.
- Louis DN, et al. WHO Classification of Tumours of the Central Nervous System (5th ed.). 2021.
Este artículo es informativo y no sustituye un examen médico. Las decisiones de diagnóstico y tratamiento son individuales.