Spinal Meningioma: Signs, Diagnosis, and Key Management

Spinal meningiomas are slow-growing tumors that arise from the meninges surrounding the spinal cord. Though often benign, their location within the confined spinal canal can cause significant neurological symptoms if untreated. Early recognition is essential to prevent permanent nerve damage and optimize outcomes.

Given their impact on mobility and quality of life, timely diagnosis and proper management are critical for successful treatment.

Spinal Anatomy and Tumor Genesis

The spinal column provides structural support and houses the spinal cord, which is surrounded by three protective meningeal layers: dura mater, arachnoid mater, and pia mater. Spinal meningiomas originate from arachnoid cap cells within the arachnoid mater, which play a role in cerebrospinal fluid (CSF) dynamics. These tumors most commonly develop in the thoracic region, followed by the cervical and lumbar areas. Their slow growth can still lead to significant neural compression due to the vertebral column’s rigidity.

The development of spinal meningiomas is linked to genetic mutations, particularly in the NF2 gene, which encodes the tumor suppressor protein merlin. Loss of merlin disrupts cell adhesion and proliferation control, promoting tumor growth. Hormonal influences are also suspected, as these tumors are more prevalent in postmenopausal women, suggesting a role for estrogen and progesterone receptors.

As the tumor enlarges, it compresses the spinal cord and nerve roots, leading to neurological dysfunction. Intradural-extramedullary meningiomas, the most common type, expand within the dura but outside the spinal cord, gradually displacing neural tissue. Less common extradural or en plaque variants infiltrate surrounding structures, complicating surgical removal. Due to their slow progression, symptoms may be subtle initially, leading to delayed diagnosis.

Common Clinical Signs

Spinal meningiomas often present with gradually worsening symptoms, making early detection challenging. The most frequent initial complaint is localized back pain, often mistaken for musculoskeletal strain or degenerative spine disease. This pain is typically dull, non-radiating, and worsens with activity or certain postures. Unlike mechanical back pain, tumor-related discomfort is often nocturnal and unresponsive to standard pain relief.

As neural compression progresses, sensory disturbances emerge in a dermatomal distribution, leading to numbness, tingling, or a “pins and needles” sensation. Thoracic meningiomas can cause a tight band-like sensation around the torso, while cervical and lumbar tumors may affect sensation in the upper or lower extremities. Proprioceptive deficits can result in unsteady gait and difficulty navigating uneven surfaces.

Motor dysfunction follows sensory impairment, beginning with subtle weakness or muscle fatigue. Patients may struggle with fine motor tasks, such as buttoning shirts or gripping objects, particularly with cervical involvement. Lower spinal tumors can cause progressive leg weakness, leading to frequent tripping or an altered gait. Hyperreflexia and muscle spasticity are common, reflecting upper motor neuron involvement. Severe cases may result in muscle atrophy and significant mobility impairment.

Autonomic dysfunction occurs in advanced cases, particularly with lower thoracic or lumbar tumors. Bladder disturbances like urinary urgency, hesitancy, or incontinence may develop due to disrupted neural control of the detrusor muscle. Bowel dysfunction, though less common, can manifest as constipation or, in severe cases, fecal incontinence. Sexual dysfunction may also arise, particularly in men. These symptoms indicate significant spinal cord compromise and require urgent evaluation.

Diagnostic Imaging Methods

Advanced imaging techniques are essential for identifying spinal meningiomas, determining tumor size, location, and impact on surrounding structures. Magnetic resonance imaging (MRI) with contrast is the preferred modality due to its superior soft tissue resolution. These tumors typically appear isointense or hypointense on T1-weighted images and hyperintense on T2-weighted sequences, with uniform enhancement after gadolinium administration. The presence of a dural tail sign—linear enhancement extending from the tumor along the dura—strongly suggests a meningioma.

Computed tomography (CT) is useful for assessing bony involvement. While spinal meningiomas are usually non-invasive, some may cause reactive hyperostosis of adjacent vertebrae, a finding more easily detected on CT scans. CT myelography, which involves injecting contrast into the cerebrospinal fluid, can be useful for patients unable to undergo MRI.

Functional imaging techniques, though less commonly used, provide additional insights in select cases. Positron emission tomography (PET) with fluorodeoxyglucose (FDG) is not routinely used, as these tumors exhibit low metabolic activity. However, PET imaging can help differentiate atypical or anaplastic variants in suspected malignancies. Advanced MRI techniques like diffusion tensor imaging (DTI) and perfusion-weighted imaging can further characterize tumor consistency and vascularity, aiding in surgical planning.

Histopathological Subtypes

Spinal meningiomas have distinct histopathological subtypes, each with unique cellular architecture and growth patterns. Most are benign (WHO Grade I), but their microscopic features influence surgical resectability and recurrence risk.

Meningothelial

The meningothelial variant is the most common subtype, consisting of uniform, polygonal cells with indistinct borders, creating a syncytial appearance. These tumors have a lobulated architecture and minimal fibrous stroma. A hallmark feature is whorled cellular arrangements, which may form psammoma bodies—concentric calcifications. Meningothelial meningiomas generally have a soft consistency, making them easier to resect. Immunohistochemically, they express epithelial membrane antigen (EMA) and vimentin. Their recurrence rate is low following complete excision.

Fibroblastic

Fibroblastic meningiomas are composed of elongated spindle-shaped cells arranged in interwoven fascicles, resembling fibrous connective tissue. These tumors contain abundant collagen, giving them a firm texture that can complicate surgical removal. Unlike meningothelial variants, they lack whorled architecture but may still contain psammoma bodies. Immunohistochemical staining shows strong vimentin positivity with variable EMA expression. While benign, their fibrous nature makes them more challenging to distinguish from schwannomas or solitary fibrous tumors.

Transitional

Transitional meningiomas combine features of meningothelial and fibroblastic subtypes, with both syncytial and spindle-shaped cells. This results in a varied texture, with soft areas and fibrotic regions. The defining characteristic is the presence of concentric whorls interspersed with collagen-rich areas, often leading to extensive psammoma body formation. Immunohistochemically, they express both EMA and vimentin. Their behavior is generally indolent, with a low recurrence rate after gross total resection.

Psammomatous

Psammomatous meningiomas are distinguished by an extensive presence of psammoma bodies, which can sometimes outnumber tumor cells. The high degree of mineralization gives these tumors a firm, rock-like consistency, complicating surgical removal. Histologically, they contain meningothelial or transitional elements interspersed with dense calcifications. Their rigid structure makes them more easily detected on CT scans. While their growth is slow, extensive calcification can contribute to spinal cord compression, necessitating intervention.

Management Considerations

Treatment depends on tumor size, location, and neurological symptoms. For asymptomatic or minimally symptomatic cases, careful observation with periodic imaging may be appropriate, particularly in elderly patients or those with significant comorbidities. However, surgical resection remains the primary treatment due to the risk of neurological deterioration.

The goal of surgery is gross total resection while preserving spinal cord function. Microsurgical techniques allow precise dissection from neural structures. In cases where the tumor adheres to critical areas, subtotal resection may be necessary to prevent damage. Most patients experience significant symptom relief, though recovery depends on the duration and severity of preoperative deficits.

For tumors that cannot be fully excised, radiation therapy may control residual growth. Stereotactic radiosurgery delivers focused radiation while sparing surrounding tissue, making it useful for inoperable or recurrent meningiomas. Conventional radiotherapy is generally reserved for higher-grade or aggressive variants. Long-term follow-up with serial imaging is essential to detect recurrence early.

Prognostic Factors

Outcomes depend on tumor grade, location, and the extent of surgical resection. WHO Grade I meningiomas have an excellent prognosis when completely removed, while higher-grade variants exhibit more aggressive behavior and higher recurrence rates. The Simpson grading system, which categorizes surgical removal extent, remains a useful predictor of recurrence.

Tumor location also affects surgical success. Thoracic meningiomas are often more accessible, while cervical and lumbar tumors pose greater technical challenges. Extensive dural involvement or en plaque growth patterns increase the likelihood of residual disease. Preoperative neurological status is critical, as severe deficits may only partially improve after surgery.

Possible Complications

Surgical treatment carries risks, including postoperative neurological deterioration due to spinal cord manipulation or ischemic injury. Cerebrospinal fluid leakage can occur, increasing the risk of meningitis or pseudomeningocele formation.

Recurrence is a concern, particularly for tumors that cannot be fully excised. While benign meningiomas have a low recurrence rate after complete removal, subtotal resections may require adjuvant radiation therapy. Long-term surveillance with periodic MRI scans is crucial to detect regrowth before significant neurological compromise develops.