Intramedullary Spinal Cord Tumors — Symptoms, Diagnosis, Surgery and Prognosis

Most readers benefit from reviewing this Quick Summary together with the sections on Symptoms, Diagnostic Imaging, and Surgical Treatment. Later sections provide more detailed explanations intended for patients seeking a deeper understanding before treatment decisions are made.

What Are Spinal Cord Tumors

Spinal cord tumors, also called intramedullary tumors, are tumors that arise within the spinal cord itself.

The main intramedullary tumor types include ependymoma, astrocytoma, and less commonly hemangioblastoma and other rare glial tumors and metastasis.

Image: Spinal tumors can be located in three different areas (from left to right): intramedullary (inside the spinal cord, e.g., ependymoma or astrocytoma), intradural-extramedullary (inside the spinal membrane but outside the cord, e.g., meningioma or schwannoma), or extradural (outside the spinal membrane, e.g., bone metastases or vertebral tumor).

How Common Are Intramedullary Tumors

Intramedullary spinal cord tumors are uncommon, representing only about 5–10% of all spinal tumors.

Among all spinal tumors:

• only 5–10% of all spinal tumors are intramedullary tumors
• about 55–65% are extradural tumors, most commonly metastatic lesions
• approximately 30–40% are intradural tumors (e.g., schwannoma, meningioma)

Although uncommon, these tumors are neurologically important because progressive damage to the spinal cord may occur even during slow tumor growth.

Which Tumors Occur Inside the Spinal Cord

The majority of intramedullary tumors include:

• ependymoma, approximately 60–70%
• astrocytoma, approximately 25–35%
• hemangioblastoma, metastasis and other rare tumors occurring less frequently

In adults, ependymoma is the dominant tumor type, while astrocytomas are relatively more frequent in pediatric patients.

Distribution Along the Spinal Cord

Intramedullary tumors may occur at any spinal level:

• cervical spinal cord — about 40–45%
• thoracic spinal cord — about 35–40%
• conus medullaris — about 15–20%

Ependymomas commonly arise near the central canal and lower spinal cord segments.

Basic Anatomy Relevant for Symptoms

The spine consists of 5 main regions: cervical, thoracic and lumbar spine, sacrum and coccyx (tailbone)

Image: Regions of the spine: cervical (neck), thoracic (mid-back), lumbar (lower back), sacral, and coccygeal (tailbone). Inside the spine is the spinal canal, which houses the spinal cord. The spinal cord ends at the level of the L1 vertebra, so the spinal canal of the lumbosacral region contains only nerve roots (either individually or as the cauda equina). Learn more on our Spine anatomy page.

From outside toward the spinal cord, anatomical layers include:

• vertebral bone
• epidural space
• dura mater
• arachnoid membrane
• cerebrospinal fluid
• spinal cord

The spinal cord contains pathways responsible for movement, sensation, coordination, and bladder and bowel control. Damage to these pathways leads to various combinations of neurological deficits. Neurological deficits therefore appear below the tumor level.

Image: The spine is composed of vertebrae stacked one on top of the other. Inside, these bones form the spinal canal, which acts as a protective tunnel. The spinal cord and the nerve roots that branch off from it pass through this canal.

Image: The spinal cord and its nerve roots. Dura and other anatomical layers. Between the arachnoid layer and the nerve elements, clear cerebrospinal fluid (CSF) circulates.

How Intramedullary Tumors Develop

Intramedullary tumors arise from cells normally present within the spinal cord.

Like other tumors in the body, intramedullary tumors develop as a result of genetic alterations (mutations) occurring in previously normal cells. Some genes become activated (proto-oncogenes transforming into oncogenes), while others become inactivated (tumor suppressor genes). Such genetic changes occur continuously in many cells. Under normal circumstances, cellular repair mechanisms and immune surveillance eliminate most abnormal cells. Occasionally, however, altered cells escape these control mechanisms and continue to proliferate, leading to tumor formation. Some tumors remain biologically slow growing, while others may acquire additional genetic alterations associated with more aggressive behavior.

The precise causes of these genetic changes are often unknown. They may occur spontaneously or rarely be associated with exposure to ionizing radiation or prior medical treatment. For most intramedullary spinal tumors, however, no single identifiable cause can be established.

Most intramedullary tumors are not inherited. Nevertheless, certain rare genetic syndromes, such as neurofibromatosis or von Hippel–Lindau disease, may increase susceptibility to tumor development. In the majority of patients, the tumor develops without a recognizable hereditary cause.

Mechanisms of Spinal Cord Damage by Intramedullary Tumor

Neurological damage develops mainly through:

• gradual compression of spinal cord or/and neural fibers
• disturbance of spinal cord blood circulation
• destruction of functional spinal pathways
• obstruction of cerebrospinal fluid flow and syringomyelia formation

Because growth can be slow, some tumors may become large before severe neurological symptoms appear.

Ependymoma, Astrocytoma and Hemangioblastoma — Biological Differences

An ependymoma usually grows centrally within the spinal cord and often forms a relatively clear border separating tumor from normal tissue. This characteristic frequently allows complete surgical removal.

According to current classifications, spinal cord ependymomas are divided into:

• WHO Grade I — myxopapillary ependymoma and subependymoma
• WHO Grade II — classic (typical) ependymoma
• WHO Grade III — anaplastic ependymoma (more aggressive and faster growing)

Most spinal ependymomas are low-grade tumors (WHO Grade I–II), representing the large majority of cases, while anaplastic (Grade III) variants are uncommon.

Ependymomas may therefore appear as:

• Myxopapillary ependymoma — typically arising in the conus medullaris or filum terminale
• Classic intramedullary ependymoma
• Anaplastic ependymoma — a rare high-grade form

An astrocytoma typically infiltrates surrounding spinal cord tissue without a clear boundary. Surgical treatment therefore prioritizes preservation of neurological function rather than radical excision.

Intramedullary astrocytomas show a broader biological spectrum:

• WHO Grade I — pilocytic astrocytoma (slow-growing, more common in children)
• WHO Grade II — diffuse astrocytoma (most common spinal astrocytoma)
• WHO Grade III–IV — high-grade or malignant astrocytomas (less frequent but associated with poorer prognosis)

Clinical series indicate that approximately 70–80% of spinal cord astrocytomas are low-grade (Grade I–II), whereas 20–30% represent higher-grade tumors, which demonstrate more aggressive behavior and limited surgical resectability.

Hemangioblastomas are rare, highly vascular tumors that may develop within the spinal cord, most commonly in adults. They are usually benign and slow growing but can cause progressive neurological symptoms due to spinal cord compression or associated fluid cavity formation (syringomyelia). Some hemangioblastomas occur sporadically, while others are associated with von Hippel–Lindau disease. Because these tumors often have a well-defined border, surgical removal is frequently effective when treatment becomes necessary. Asymptomatic tumors are frequently monitored with periodic MRI examinations, and approximately one third to one half of incidentally detected lesions may initially be managed without surgery when neurological function remains stable.

Besides the above-mentioned tumors less common tumors may also occur within the spinal cord, including gangliogliomas, primary spinal cord lymphomas, germ cell tumors, melanocytic tumors, and intramedullary metastases. In some patients, MRI appearance, tumor location, or associated systemic disease may raise suspicion for a specific diagnosis even before surgery. Importantly, not all intramedullary tumors require primary surgical removal. Certain lesions, such as lymphoma, germinoma, or metastatic tumors, may be treated primarily with radiotherapy or chemotherapy. However, in many cases the definitive diagnosis — and therefore the optimal treatment strategy — can only be established after histopathological (PH) analysis obtained during biopsy or surgical treatment.

Association With Syringomyelia

A fluid cavity inside the spinal cord, known as syringomyelia, frequently accompanies intramedullary tumors, particularly ependymomas.

This develops because tumor growth disturbs normal cerebrospinal fluid circulation inside the spinal cord.

Symptoms Depending on Tumor Level

Symptoms caused by intramedullary spinal cord tumors usually develop slowly and reflect progressive involvement of spinal cord pathways.

Diffuse back pain is often the earliest presenting symptom, but unlike extramedullary spinal tumors, this pain is typically poorly localized, non-radicular, and frequently described as deep burning or dysesthetic discomfort rather than sharp nerve-root pain. The pain commonly worsens at night or during rest, which may represent one of the earliest warning signs and often precedes clear neurological deficits. Radicular pain resembling sciatica is uncommon because the tumor arises within the spinal cord itself rather than compressing exiting nerve roots.

As tumor growth progresses, neurological symptoms become dominant, including sensory disturbance, gait instability, motor weakness, and later autonomic dysfunction below the tumor level.

Cervical spinal cord

Patients may experience:

• weakness involving arms and legs
• reduced hand coordination
• progressive walking instability
• sensory disturbance across hands and legs
• neck discomfort
• in advanced cases breathing difficulty

Thoracic spinal cord

Typical presentation includes:

• gradual difficulty walking
• stiffness of the legs
• sensory disturbance across the trunk
• balance impairment

Conus medullaris

Common symptoms include:

• impaired bladder control
• bowel dysfunction
• sexual dysfunction
• numbness in the saddle region
• leg weakness
• leg pain

Diagnostic Imaging

Spinal cord tumors are usually diagnosed with contrast-enhanced MRI of the spine, because MRI shows whether the lesion is inside the spinal cord, how far it extends, how it enhances, and whether it is more suggestive of ependymoma, astrocytoma, hemangioblastoma, inflammation, or another spinal cord disorder.

MRI demonstrates:

• precise tumor location
• if there is a clear demarcation between the tumor and the spinal cord
• spinal cord enlargement
• contrast enhancement pattern
• associated cysts or syrinx
• surrounding edema

Ependymomas usually produce central symmetric expansion of the spinal cord, while astrocytomas more commonly appear diffuse or eccentric.

Magnetic resonance imaging also plays an essential role in differential diagnosis, since not every intramedullary lesion represents a tumor. Conditions that may mimic intramedullary tumors include multiple sclerosis, neuromyelitis optica spectrum disorders, transverse myelitis, spinal cord infarction, cavernous malformations, and rare infections or granulomatous diseases. Careful analysis of lesion location, enhancement pattern, associated edema, and clinical progression helps distinguish true tumors from non-neoplastic spinal cord disorders.

Imaging of the Entire Spine and Brain

MRI of the entire spine and brain is often recommended for intramedullary spinal cord tumors to exclude multiple lesions, associated brain disease, tumor spread, or conditions that may change surgical planning.

Image: Spinal MRI shows a spinal cord tumor (ependymoma) – red arrow, which causes cysts to form within the cord both above and below the tumor (yellow arrow).

Treatment: Observation Versus Surgery

Observation may be considered for selected intramedullary spinal cord tumors when neurological function is stable, symptoms are minimal, and MRI does not show tumor growth or signs of increasing spinal cord risk.

Approximately 10–20% of patients may initially undergo monitoring with periodic MRI examinations. Observation is usually chosen when neurological function remains preserved, tumor growth appears slow, or imaging findings do not clearly indicate immediate risk of spinal cord injury. Because intramedullary tumors may enlarge gradually while neurological deficits remain mild, even relatively large tumors can occasionally be discovered before significant functional impairment develops.

However, long-term follow-up shows that many of these tumors eventually require surgical treatment as growth or neurological symptoms progress. In clinical practice, more than half of initially observed patients ultimately undergo surgery during follow-up once signs of spinal cord compromise appear.

The decision to observe rather than operate therefore reflects a balance between two risks: early surgery may temporarily worsen neurological function, while delayed treatment may allow irreversible spinal cord damage to develop.

Indications for Surgery

Surgery is recommended for an intramedullary spinal cord tumor when one or more signs suggest increasing neurological risk:

• neurological deficit progresses
• tumor enlargement is documented
• spinal cord compression threatens permanent damage
• diagnosis remains uncertain

Intramedullary tumors may become large with relatively mild symptoms because the spinal cord adapts gradually. Delayed treatment increases the risk of irreversible neurological damage. In such situations, treatment decisions may be complex, since neurological function may significantly temporarily worsen after surgery even when intervention is necessary to prevent permanent spinal cord damage.

Surgical Technique

Surgery is performed through a posterior approach with the patient positioned prone (lying on their stomach, with the incision made on the back).

Typical steps include:

• skin incision and exposure of vertebrae
• Laminectomy or Laminoplasty: The surgical approach involves either a laminectomy (the permanent removal of the vertebral arches to provide access) or a laminoplasty (the reconstruction of the spinal canal, where the removed laminae are replaced and fixed back into their original position following tumor excision to preserve spinal stability and protection).
• opening of the dura mater
• microsurgical opening of the spinal cord
• identification of tumor boundary
• maximal safe tumor removal is the main surgical principle in the treatment of intramedullary spinal cord tumors, but the achievable extent of resection depends strongly on tumor biology. In ependymomas and hemangioblastomas, a clear plane usually exists between the tumor and normal spinal cord tissue, which means that gross total resection (GTR) can often be safely achieved and is typically the preferred treatment. In contrast, most intramedullary astrocytomas grow infiltratively within the spinal cord and do not have a distinct surgical boundary. Complete removal is therefore generally possible only in selected pilocytic (WHO Grade I) astrocytomas. In diffuse astrocytomas (WHO Grade II–IV), attempts at radical resection are usually avoided because aggressive tumor removal mainly increases the risk of permanent neurological deficits without clear improvement in outcome. For this reason, surgery in astrocytomas focuses on maximal safe tumor removal while prioritizing preservation of neurological function, in accordance with current treatment guidelines.

Continuous intraoperative neurophysiological monitoring is used to protect motor and sensory pathways from surgical manipulation.

Image: The image on the left shows the removed posterior arches of the spinal canal (laminae) to access the spinal canal and spinal cord within it. The dura mater (the spinal cord’s protective envelope) is opened, followed by a midline incision of the spinal cord to reach the tumor. Whenever possible, the tumor’s margin is identified, and it is separated from the spinal cord and removed (in this case, using a specialized surgical aspirator called CUSA). The entire procedure is performed under general anesthesia with neurophysiological monitoring, which tracks the spinal cord pathways to ensure they are not damaged during manipulation. After the tumor is removed, the dura is sutured, and the laminae are re-fixed (laminoplasty, as shown in the image on the right).

Possible Complications

Local complications may include:

• Cerebrospinal fluid leakage
• Infection
• Bleeding
• Postoperative spinal instability

Neurological Worsening After Surgery

Temporary neurological worsening can occur after intramedullary spinal cord tumor surgery because the operation requires opening the spinal cord and manipulating delicate motor and sensory pathways and their blood supply. Recovery often develops gradually over weeks or months. Outcome largely depends on the spinal cord condition before surgery.

Adjuvant Treatment

Radiotherapy or other adjuvant treatment may be required after incomplete removal of an intramedullary spinal cord tumor, tumor progression, or higher-grade pathology, but it is not automatically needed after complete removal of a low-grade ependymoma.

1) Radiotherapy represents the most common adjuvant treatment following incomplete tumor removal or in higher-grade tumors. Treatment is usually delivered as fractionated external beam radiotherapy, while stereotactic radiotherapy may be considered in selected cases or for tumor recurrence. Chemotherapy is rarely required.

After complete removal of low-grade ependymoma, further therapy is often unnecessary.

In intramedullary astrocytomas, treatment strategy differs significantly. Because most astrocytomas infiltrate normal spinal cord tissue, subtotal (incomplete) resection is frequently performed to preserve neurological function. In low-grade (WHO Grade II) astrocytomas, postoperative management may include careful radiological follow-up rather than immediate radiotherapy, especially when neurological function is stable. Adjuvant radiotherapy is more commonly considered in cases of tumor progression, symptomatic residual tumor, or higher-grade disease.

Since intramedullary astrocytomas frequently affect children and young adults, the potential long-term consequences of radiotherapy must be carefully considered before treatment. Possible complications include permanent neurological worsening, radiation-induced myelopathy, spinal deformities such as scoliosis, impaired spinal growth, and late radiation-related tissue injury. For this reason, the indication for radiotherapy is evaluated cautiously, and all potential risks must be discussed in detail with patients and, in pediatric cases, with parents before treatment decisions are made.

2) Chemotherapy is used selectively in intramedullary astrocytomas, particularly in higher-grade tumors (WHO Grade III–IV) or in cases of tumor progression when further surgery or radiotherapy is not feasible. The most commonly used agent is temozolomide (Temodar), extrapolated from its established role in intracranial gliomas. Its benefit in spinal cord astrocytomas remains limited and variable, and treatment decisions are individualized.

Follow-Up After Treatment

MRI surveillance typically includes:

• Examination three months after surgery
• Six-month control
• Annual follow-up thereafter

Long-term monitoring remains essential.

Emerging and Investigational Treatment Approaches in Intramedullary Tumors

A number of new treatment strategies are currently being developed for central nervous system tumors, primarily for brain tumors, but many of these approaches are increasingly being explored for intramedullary spinal cord tumors as well. These include targeted drug delivery techniques, convection-enhanced delivery (CED), focused ultrasound–assisted treatment, implantable drug-releasing systems, nanomedicine-based therapies, as well as emerging molecular and immunotherapy-based approaches aimed at improving tumor control while minimizing damage to normal nervous tissue and overcoming biological barriers such as the blood–spinal cord barrier that limit conventional therapies.

At present, most of these methods remain investigational and are available mainly within clinical trials or specialized research programs. Some techniques have shown promising early results, while others are still undergoing safety and efficacy evaluation before wider clinical adoption.

Patients who are offered participation in experimental or investigational treatment programs may consider obtaining an independent medical opinion before proceeding. This also applies to treatment methods promoted outside established academic or clinical research institutions, particularly when proposed therapies are not supported by peer-reviewed clinical evidence. If needed, treatment proposals can be reviewed independently to help assess potential benefits, risks, and realistic expectations based on current neurosurgical and neuro-oncological standards.

Management of Recurrence

Tumor recurrence may require repeat surgery, radiotherapy, or combined treatment depending on tumor biology and neurological condition. Recurrence risk differs substantially between tumor types. Intramedullary astrocytomas, particularly diffuse tumors treated with subtotal resection, demonstrate recurrence in approximately 40–50% of cases, reflecting their infiltrative growth pattern. In contrast, spinal ependymomas show significantly lower recurrence rates, reported in roughly 5–10% of patients, most commonly after incomplete tumor removal or in higher-grade variants.

Distinguishing true tumor recurrence from postoperative scar tissue or treatment-related changes may sometimes be challenging on MRI alone. Recurrent tumors typically demonstrate progressive enlargement and persistent or increasing contrast enhancement over time, whereas postoperative scarring usually remains stable or gradually decreases during follow-up examinations. For this reason, comparison with previous MRI studies and clinical evolution remains essential before additional treatment is recommended.

Long-Term Prognosis

The long-term prognosis of intramedullary spinal cord tumors is usually better for completely removable ependymomas and more variable for astrocytomas, especially when neurological function is already impaired before treatment.

Complete removal of ependymoma often provides long-term disease control, while astrocytoma outcome varies significantly according to tumor grade. Low-grade astrocytomas (WHO Grade I–II) may follow a relatively slow clinical course, whereas high-grade astrocytomas (WHO Grade III–IV) are associated with more aggressive progression and represent the group with the shortest survival, with reported average survival times of approximately 12–18 months despite treatment.

The most important predictor of recovery remains neurological status at the time of surgery. Long-term functional independence often depends more on preoperative neurological status than on tumor size alone.

Why Neurosurgical Opinions May Differ in Spinal Cord Tumors

Management of intramedullary spinal cord tumors often involves complex decision-making in which more than one medically reasonable approach may exist. Differences between neurosurgical opinions do not necessarily indicate diagnostic error, but rather reflect careful balancing between tumor control and preservation of neurological function.

Neurosurgical recommendations may differ regarding:

How MRI Findings Are Interpreted in Complex Cases

Whether imaging represents a true tumor, inflammatory disease, postoperative change, or treatment-related alteration may not always be immediately clear.

When Early Surgery Is Preferred Over Observation

Some specialists may recommend early surgery to prevent future neurological deterioration, while others may advise careful monitoring when neurological function remains stable.

How Neurological Risk Influences the Treatment Decision

Surgeons may differ in estimating the likelihood of temporary or permanent neurological worsening after tumor removal, particularly in patients with minimal symptoms despite large tumors.

How Much of the Tumor Should Be Safely Removed

In certain tumors — most commonly intramedullary astrocytomas — aggressive resection may improve long-term tumor control but substantially increase neurological risk, whereas subtotal removal is often intentionally performed to preserve spinal cord function when clear tumor boundaries are absent.

Which Surgical Strategy Is Most Appropriate

Opinions may vary regarding surgical approach, extent of bone removal, need for reconstruction, or intraoperative techniques used to minimize spinal cord injury.

When Additional (Adjuvant) Treatment Is Necessary

Recommendations may differ concerning postoperative radiotherapy, timing of radiation, or the need for additional oncological treatment depending on tumor type and histology.

How Postoperative MRI Findings Are Interpreted

Specialists may disagree whether imaging changes represent tumor recurrence, postoperative scar tissue, radiation effects, or normal healing processes.

Because spinal cord tissue has limited capacity for recovery after injury, treatment decisions frequently involve weighing competing risks rather than choosing between clearly right or wrong options. For this reason, independent neurosurgical evaluation may help patients better understand available strategies and expected outcomes.

Frequently Asked Questions About Spinal Cord Tumors