Presentation
Seizure and left sided weakness.
Patient Data
Pre and post-contrast CT images demonstrating a large heterogeneous mass within the left thalamus and basal ganglia, characterized by prominent rim enhancement and central hypoattenuating/necrotic component, and promoting mass effect with left lateral ventricle compression, midline shift and slight uncal herniation. Surrounding edema is also present.
The patient found it difficult to remain still; as a result many sequences are severely degraded by motion artefact. MR spectroscopy could not be performed.
There is a large intra-axial mass centered on the left thalamus and basal nuclei.
This demonstrates areas of irregular nodular contrast enhancement with central areas of non-enhancement. The enhancing margin shows diffusion restriction and increased perfusion. There is surrounding abnormal FLAIR hyperintensity extending into the white matter of the frontal and temporal lobes, left insula, inferiorly into the left and across midline into the right thalamus.
There is marked mass effect on the third ventricle, dilation of both lateral ventricles, and periventricular FLAIR hyperintensity in keeping with transependymal fluid shift.
Conclusion:
Mass consistent with high-grade glial series tumor centered on left thalamus with extension into the right thalamus. Mass-effect on the third ventricle causing obstructive hydrocephalus.
Case Discussion
The patient was submitted to a tumor stereotactic biopsy and the suspected diagnosis was confirmed by the histology.
Histology
MICROSCOPIC DESCRIPTION: The sections shows small fragments of a densely hypercellular glial tumor. This is composed predominantly of markedly pleomorphic astrocytic cells with fibrillary morphology. A quantitatively smaller component of pleomorphic oligodendroglial cells is also noted. Scattered mitotic figures are identified. There is focal microvascular proliferation with multilayering of atypical cells around vessel lumena. Areas of necrosis are also seen. These incorporate thin walled necrotic blood vessels.
IMMUNOHISTOCHEMISTRY:
- GFAP positive in tumor and reactive astrocytes; negative in oligodendroglial cells.
- NogoA positive in oligodendroglial cells, negative in tumor and reactive astrocytes.
- Nestin positive (high)
- IDH-1 R132H negative (not mutated)
- ATRX positive (not mutated)
- MGMT negative (likely methylated)
- p53 positive
- Topoisomerase labeling index: Approximately 40%. The features are of IDH-1 wild-type glioblastoma multiforme.
FINAL DIAGNOSIS: IDH-1 wild-type glioblastoma multiforme (WHO Grade IV).
Note: Although this is tumor is entirely consistent with an IDH wild-type glioblastoma, immunohistochemical IDH1 R132H negativity does not categorically exclude a non-IDH1 R132H mutation. To be absolutely certain one would need to perform IDH sequencing.
In this age-group the likelihood of such a mutation is remote.
Unable to process the form. Check for errors and try again.