Gliomatosis, multifocal glioma

Case contributed by A.Prof Frank Gaillard

Presentation

Seizures. Recently diagnosed, untreated, breast cancer.

Patient Data

Age: 70 years
MRI

 

A high T2 signal (T2 not shown) left parietal lesion demonstrates no enhancement and no internal diffusion restriction (also not shown). Prominent FLAIR suppression.

Extensive white matter FLAIR hyperintensity with mass effect crosses the corpus callosum. Right peritrigonal nodular contrast enhancement. 

Conclusion: Low grade left parietal tumour (likely astrocytoma) with gliomatosis and higher grade components particularly on the right. 

Pathology

The patient went on to the dominant left parietal circumscribed lesion excised.

Histology

MICROSCOPIC DESCRIPTION:

Sections show fragments of a moderately hypercellular astrocytic glioma with extensive microcyst formation. Tumour cells show moderate nuclear and cellular pleomorphism. Scattered mitotic figures are identified (up to 2 per 10hpf). No microvascular proliferation or necrosis are identified.

Immunohistochemistry results show tumour cells stain:

  • GFAP Positive
  • Nestin Positive (high)
  • NogoA Positive
  • IDH-1 R132H  positive cytoplasmic staining = (mutated)
  • ATRX loss of normal nuclear staining = Negative (mutated)
  • MGMT loss of normal  nuclear staining, except in endothelial cells of blood vessels (internal positive control) = Negative (likely methylated)
  • p53 Positive p16 CDKN2A Positive
  • Topoisomerase labelling index: 5%. 

The infrequent mitoses and low Topoisomerase proliferation index (5%) favour a diagnosis of low-grade glioma (WHO II).

  • FINAL DIAGNOSIS: IDH-1 mutant Diffuse Astrocytoma (WHO Grade II).

Histology courtesy of Dr Te Whiti Rogers 

Case Discussion

This case illustrates the limitations of histology when multiple components are present. The left parietal lesion appears low grade, but clearly there is a higher grade component in the right hemisphere. 

This case also demonstrates that in the elderly multiple malignancies may be present and just because there is a history of one, does not necessarily mean that other lesions are metastatic. 

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Case information

rID: 50663
Case created: 16th Jan 2017
Last edited: 17th Jan 2017
Inclusion in quiz mode: Included

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