Intramedullary tumours | Property | Ependymoma | Astrocytoma | Haemangioblastoma |
Numbers | ㅤ | Most common intramedullary tumour (adult) | 2nd most common (adult) 30% Most common in children | 3 most common (adult) 3-13% |
Location | ㅤ | 50% Cervicothoracic 50% Lumbar sacral/filum | Cervicothoracic | ㅤ |
Origin | ㅤ | Ependymal cells | Glial cells | Haemangioblast |
MRI features | T1 | Variable | Hypointense | Iso- to hypointense |
ㅤ | T2 | Hypointense | Hyperintense | Iso- to hyperintense (enlarged feeding and draining |
ㅤ | Location | Central | More eccentric | Usually superficial |
ㅤ | Enhancement | Homogenous | Heterogenous (30% enchances; none with LGG; intense in pilocytic astrocytomas and HGG) | Intense |
ㅤ | Margins | Generally distinct | Poorly defined | Distinct nodule |
ㅤ | Syringomyelia/Cyst | Often associated | Less common (pilocytic astrocytomas may have an associated cyst)-20% | Very commonly associated with a cyst |
ㅤ | Haemorrhage | Hemosiderin caps near the poles of the tumour | ㅤ | ㅤ |
ㅤ | Metastasis/Seeding | High | ㅤ | ㅤ |
Histology | Subtypes WHO grade | Subependymoma (rare) 1 | Pilocytic astrocytoma (rare) 1 | Haemangioblastoma 1 |
ㅤ | ㅤ | Ependymoma 2 | Low grade astrocytoma 2 | ㅤ |
ㅤ | ㅤ | Anaplastic ependymoma 3 | Anaplastic astrocytoma 3 | ㅤ |
ㅤ | ㅤ | ㅤ | Glioblastoma 4 | ㅤ |
ㅤ | Microscopic features of commonest subtype | Sheets of uniform cells with oval nuclei and fine cytoplasmic processes Perivascular pseudorosettes | Well differentiated neoplastic astrocytes within microcystic tumour matrix (No necrosis or microvascularproliferation) | Two main components: endothelial cells and pericytes; large, vacuolated stromal cells containing lipid Rosenthal fibres in cyst and syrinx walls |
ㅤ | ㅤ | Mitoses rare/absent | Mitoses: Ki-67/MIB-1 <4% | Mitoses usually absent (MIB-1: 0-2%) |
ㅤ | Immuno-histochemistry | GFAP S-100 protein, Vimentin | GFAP, Vimentin (moreconsistent in higher grade) | Stromal cells lack endothelial cell markers (negative in RCC) but are positive for D2-40 Ab and inhibin-A (positive in RCC), Vimentin, VEGF |
Syndromic associations | ㅤ | NF2 (chromosome 22q12) | NF1 (chromosome 17q11) TP53 germline mutations / Li-Fraumeni syndrome Ollier's disease (Inherited multiple enchondromatosis 1) | VHL (chromosome 3p25) |
Management | Goal | GTR STR + EBRT | GTR (difficult) STR for exophytic tumours Biopsy for non exophytic tumours | GTR |
ㅤ | Potential for GTR | Yes | Less common | Yes |
ㅤ | RT | for STR | for high-grade tumors, inoperable tumors, tumors remaining after surgery, and recurring tumors. | No SRS (spinal cord injury) |
ㅤ | Chemo | ㅤ | TMZ (high grade astrocytoma) | ㅤ |
Outcome | Good prognostic factor | Patient age younger than 40 years. Tumors with a lumbosacral location. Myxopapillary histologic findings. A grade of WHO grade I. Tumors amenable to GTR or STR. Good preoperative function of the patient. | tumor histology, tumor grade, age, and performance status. | Minimal or no preoperative neurologic deficits. Lesions smaller than 0.5 cm. Dorsally located lesions. Total surgical removal of the lesion. |
ㅤ | Survival | 10 yr OS 70-100% | 5 years OS 55-100% With high-grade tumors in adults and children, the median survival time is poor (4-10 months) despite surgery and EBRT. | ㅤ |
ㅤ | Functional | ㅤ | ㅤ | 41-68% of patients experience improvement of neurologic function. Another 32-84% have stabilization of their preoperative function. |
When to operate:
- Surgery should be performed as soon as symptoms develop
- Early intervention before severe neurological deficits maximizes functional recovery
- Patients with good preoperative walking ability (ASIA grades D and E) achieved 90.4% good outcomes vs 29.4% for non-ambulatory patients (Chamberlain 2014, PMC)
- 73.5% of patients with preoperative McCormick scores of 1-2 showed better functional improvement (Joshi 2024, PMC)
- Multiple logistic regression analysis confirmed that worse preoperative McCormick Scale scores were poor independent prognostic factors (Nakamura 2020, PMC)
- Preoperative neurological status is the strongest predictor of outcome
- Preoperative good neurological state was the strongest positive predictor of good functional outcome (p<0.05) (Chamberlain 2014, PMC)
- The most reliable predicting factor of surgical outcome was the preoperative neurological state (Chamberlain 2014, PMC)
- Patients with low preoperative McCormick scores (1 or 2) demonstrated better functional outcomes after surgery (Joshi 2024, SNI)
- Thoracic tumors require particular urgency for early treatment
- Functional outcomes of thoracic tumors were significantly poorer than those in cervical and conus medullaris regions (p=0.011) (Chamberlain 2014, PMC)
- Thoracic location was identified as a risk factor for poor outcome in univariate analysis (p=0.195) (Nakamura 2020, PMC)
- Thoracic spinal cord has increased vulnerability to surgical manipulation and poor microcirculation (Nakamura 2007, Nature)
- Complete resection should be the goal for benign tumors when feasible
- Gross total resection (GTR) was a good independent prognostic factor for spinal intramedullary ependymoma (OR 0.083, p=0.007) (Nakamura 2020, PMC)
- Complete resection rates: approximately 90% for ependymomas and hemangioblastomas vs 50-76% for low-grade astrocytomas (Chamberlain 2014, PMC)
- Adult patients with malignant intramedullary tumors treated with gross total resection had significantly better prognosis than those with subtotal resection (Chamberlain 2014, PMC)
- Rates of gross-total resection: 84% for ependymomas vs 54% for astrocytomas (p < 0.01) (Kato 2022, PubMed)
- Additional Supporting Evidence:
- Multicenter study of 1033 patients confirmed that early and radical surgical interventions are associated with better postoperative outcomes (Takami 2022, Neurospine)
- Early surgery for patients with even mild neurological disorders could facilitate functional outcomes (Nakamura 2020, PMC)
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