Glioblastoma IDH wild-type (unusual)

Case contributed by Assoc Prof Frank Gaillard


Headache and right sided weakness.

Patient Data

Age: 65 years

A large left parietal mass with evidence of internal coarse calcification. Extensive surrounding edema. No bony hyperostosis or involvement. 

A large heterogeneous mass with vivid enhancement in the left parietal region contains mixed low and high T2 signal with some peripheral cystic areas and contains multiple large flow voids. Surrounding vasogenic edema. It is difficult to be entirely sure whether this mass is intra or extra-axial. Certainly it has a broad dural abutment with a dural tail of enhancement, however, on coronal sequence, its deeper portion does not have intervening cortex between lesion and white matter. There is left-sided sulcal and lateral ventricular effacement with 7 mm midline shift toward the right but no uncal herniation. No left temporal horn dilation to suggest entrapment.

Conclusion: Large left frontal/parietal mass is favored to be either an intraaxial partially exophytic mass (e.g. glioblastoma) or an extra-axial mass which has invaded brain parenchyma (e.g. atypical meningioma).

DSA (angiography)

The mass in the left frontoparietal region is markedly hypervascular, with supply predominantly from pial vessels of the angular and parietal branches of the middle cerebral artery, with contribution from the anterior cerebral artery, with only minor supply from a normal caliber left middle meningeal artery. The striking feature is the neoangiogenesis around the periphery of the tumor, particularly on the deep aspect, with primary drainage into a central large dysplastic-appearing vein which passes to the convexity and then to the superior sagittal sinus. A smaller second vein is shown. There is rapid arteriovenous shunting. 

Conclusion: The appearance is that of a tumor and not a vascular malformation despite the marked arteriovenous shunting. The degree of hypervascularity and shunting is most unusual, particularly for a standard glioblastoma. Differential diagnoses would include astroblastoma (which can have both shunting enlarged intratumoral veins), a hypervascular metastasis such as a renal cell carcinoma (although this is not considered likely on the MRI findings of such a large solitary lesion), and hemangioblastoma. A hypervascular parenchymal tumor with drainage into an incidental developmental venous anomaly could also explain these appearances. Although there is an extra-axial component, hemangiopericytoma or atypical meningioma are virtually excluded by the angiographic pattern.

Case Discussion

The patient went on to have surgery.


MICROSCOPIC DESCRIPTION: Sections show fragments of a markedly hypercellular astrocytic glioma. Tumor cells show marked nuclear and cellular pleomorphism. Scattered mitotic figures are identified. There is prominent microvascular proliferation with multi-layering of atypical cells around vessel lumena. Extensive areas of palisaded tumor necrosis are also present.

Immunohistochemistry results show tumor cells stain:

  • GFAP: Positive
  • Nestin: Positive (high)
  • NogoA: Negative
  • IDH-1 R132H: Negative (non-mutated)
  • ATRX: Positive (non-mutated)
  • MGMT: Negative (likely methylated)
  • p53: Positive
  • p16 CDKN2A: Positive
  • Topoisomerase labeling index: 20%.
  • BRAF: No mutation detected.

Conclusion: Histologically the differential diagnoses include glioblastoma and anaplastic pleomorphic xanthoastrocytoma, however, the absence of a BRAF mutation strongly favors glioblastoma.

FINAL DIAGNOSIS: IDH-1 wild type Glioblastoma (WHO Grade IV).

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Case information

rID: 50835
Published: 10th May 2017
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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