What are the most common causes of extramedullary compressive spinal cord lesions in children aged 0‑18 years?

Extramedullary Compressive Spinal Cord Lesions in Children

In children aged 0-18 years, extramedullary compressive spinal cord lesions are most commonly caused by malignant tumors (particularly neuroblastoma in younger children and sarcomas in older children), followed by infections (epidural abscess, discitis/osteomyelitis), and less commonly by inflammatory conditions.

Neoplastic Causes (Most Common)

Malignant Tumors

• Neuroblastoma is the leading cause of extramedullary spinal cord compression in young children, accounting for 27.2-62.7% of cases, with a mean age of presentation around 20 months 1, 2.
• Sarcomas are the predominant cause in children over 5 years old, with Ewing's sarcoma (15.9%) being most frequent, followed by soft tissue sarcomas, osteogenic sarcoma, and rhabdomyosarcoma 1, 3, 2.
• Extradural tumors account for 71% of all malignant spinal cord compression cases in children, with soft tissue sarcomas and neuroblastoma comprising 54% of these extradural lesions 4.
• Other malignancies include Hodgkin's disease, germ-cell tumors, Wilms' tumor, and rarely hepatoma 3.
• Spinal cord compression is the presenting feature of a new malignancy in 75% of pediatric cases, while only 25% occur as metastatic progression or relapse 1.

Intradural Extramedullary Tumors

• Intradural extramedullary tumors represent approximately 29% of intraspinal tumors in children, with 70% being outside the spinal cord itself 4.
• Metastatic medulloblastoma accounts for 9 of 12 intradural extramedullary tumors in one series 4.
• Meningiomas and schwannomas can occur but are less common in the pediatric population compared to adults 5.

Infectious Causes

Bacterial Infections

• Epidural abscess causes acute extramedullary compression, presenting with severe back pain, fever, and rapidly progressive neurologic deficits 6.
• Vertebral body osteomyelitis and discitis are the most common spinal infections in children, particularly between ages 2-12 years, with a 3:1 male predominance 7.
• Clinical presentation includes persistent nighttime pain, low-grade fever, decreased range of motion, irritability, localized tenderness, and limping, with laboratory values showing leukocytosis and elevated ESR/CRP 7.

Chronic Infections

• Tuberculosis, schistosomiasis, and HIV-related infections can cause chronic extramedullary compression with progressive weakness, sensory loss, and sphincter dysfunction 6.

Inflammatory Causes

Spinal Column Inflammation

• Juvenile idiopathic arthritis is the most common inflammatory etiology affecting the spinal column, typically occurring in late childhood and most commonly involving the cervical spine 7.

Clinical Presentation Patterns

Symptom Hierarchy

• Motor deficit is the initial symptom in 95.6% of children with malignant spinal cord compression, making it the most sensitive early indicator 2.
• Pain occurs in 60-94% of cases, representing the second most common presenting symptom 1, 4, 2.
• Sphincter dysfunction appears in 24-43.2% of patients, typically as a later manifestation 1, 2.
• Sensory deficits are less commonly the presenting feature but develop as compression progresses 4.

Anatomic Distribution

• The thoracic spine (36.4%) and thoraco-lumbar region (18.2%) are the most common sites for extramedullary compression in children 1.
• Lumbosacral involvement occurs in 15.9-42% of cases 1, 4.
• Cervical spine involvement is less common (6.8%) except in juvenile idiopathic arthritis 7, 1.

Critical Diagnostic Timing

Delay in Diagnosis

• There is a median delay of 23-26 days between symptom onset and diagnosis in newly diagnosed cases, compared to only 7 days in patients with known malignancy experiencing relapse 1, 2.
• This diagnostic delay can result in catastrophic consequences, as the degree of neurological deficit at presentation inversely correlates with recovery potential 7, 2.

Imaging Imperatives

• MRI of the spine is the definitive diagnostic modality, demonstrating 100% diagnostic accuracy when used, compared to 85% for myelography and 83% for CT 8, 6, 4.
• Imaging the entire spine is mandatory as multilevel involvement is common in pediatric malignancies 6.

Important Clinical Pitfalls

Age-Related Patterns

• Younger children (≤3 years) have a peak incidence of extramedullary compression, primarily due to neuroblastoma, while children over 5 years are more likely to have sarcomas 1, 2.
• The median age at diagnosis across all causes is 50-52 months 1, 2.

Tumor Invasion Characteristics

• Pediatric tumors characteristically invade the spinal canal via neural foramina, causing circumferential compression rather than purely posterior compression, which has implications for surgical approach 3.

Distinguishing Features from Intramedullary Disease

• Unlike intramedullary tumors (which account for 35-40% of intraspinal tumors and are dominated by astrocytomas), extramedullary lesions more commonly present with radicular pain and have better surgical accessibility 7.