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Intradural spinal tumours
A tumour in the spinal canal is classified by compartment: extradural (mainly metastases), intradural extramedullary (schwannoma and meningioma) and intramedullary (ependymoma in adults, astrocytoma in children) — and the compartment dictates both the differential diagnosis and the type of operation.
Why it matters in the exam
The basic question: "a tumour outside the spinal cord but inside the dural sac" — this is the intradural extramedullary compartment, and its two common tumours are schwannoma (sometimes "dumbbell"-shaped, leaving through the intervertebral foramen) and meningioma (usually thoracic, in an older woman, with a dural base and calcification). Inside the cord, the commonest tumour in adults is ependymoma — central, well demarcated, with polar cysts and a haemosiderin "cap"; in children — astrocytoma, eccentric and infiltrative. An intramedullary haemangioblastoma with a cyst and nodule points to von Hippel-Lindau disease. Myxopapillary ependymoma sits in the filum terminale and presents with back pain and cauda equina root deficits. NF2 is linked to ependymomas and multiple schwannomas, and NF1 to neurofibromas.
The common presentation is back pain that worsens at night and lying down, followed by progressive myelopathy, Brown-Séquard syndrome or sphincter disturbance. Work-up: contrast MRI of the whole neuraxis, because some tumours, such as ependymoma in NF2, can be multiple. Intramedullary resection uses intraoperative neuromonitoring: motor evoked potentials (MEP) and the D-wave — a fall of more than 50% in D-wave amplitude predicts permanent motor deficit, and resection is then stopped. An intramedullary ependymoma usually allows complete removal along a cleavage plane, whereas in astrocytoma the aim is biopsy or debulking only. Vertebral body haemangioma is a common benign lesion: on CT it looks like "corduroy" on sagittal views and "polka dots" on axial views, and on MRI it is bright on T1 and T2.
Key points
- Extradural — metastases; intradural extramedullary — schwannoma and meningioma.
- Intramedullary: adult — ependymoma, child — astrocytoma.
- MEP and D-wave monitoring; fall of more than 50% — stop.
- Haemangioblastoma — VHL.
- Myxopapillary — in the filum terminale.
Summary table
| Compartment | Common tumours | Imaging sign | Treatment |
|---|---|---|---|
| Extradural | Metastases, vertebral haemangioma | Vertebral destruction, "corduroy" in haemangioma | By the primary; quiet haemangioma — follow-up |
| Intradural extramedullary | Schwannoma, meningioma, myxopapillary | Dumbbell through the foramen; dural base | Complete removal in most |
| Intramedullary in adults | Ependymoma | Central, cysts, haemosiderin cap | Complete removal with MEP and D-wave monitoring |
| Intramedullary in children | Astrocytoma | Eccentric, infiltrative | Biopsy or debulking |
| Intramedullary with cyst and nodule | Haemangioblastoma | Enhancing nodule, prominent flow voids | Resection; VHL work-up |
A free exam question
איזה מהבאים נמנה עם הקריטריונים האבחנתיים של ה- NIH עבור נוירופיברומטוזיס סוג 1 ) NF1 ?( (the question as examined, in Hebrew)
- א. שישה כתמי קפה בחלב או יותר על העור
- ב. שוונומות וסטיבולריות דו צדדיות
- ג. מספר המנגיובלסטומות ברשתית
- ד. נודולים סובאפנדימליים במוח
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Sources
- WHO Classification of Tumours: Central Nervous System Tumours, 5th edition (2021) — Spinal ependymomas; Nerve sheath tumours
- Youmans and Winn Neurological Surgery, 8th edition (2022) — Intradural extramedullary and intramedullary spinal cord tumours
- International Society of Intraoperative Neurophysiology recommendations, 2013 — Motor evoked potentials and D-wave in intramedullary surgery
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.