Anaplastic astrocytoma NOS

Case contributed by Assoc Prof Frank Gaillard


Middle aged patient presenting with a seizure.

Patient Data

Age: Adult

MRI of the brain demonstrating a left occipito-temporal mass which has high T2 signal, heterogeneous low T1 signal (cystic change? necrosis?) with only moderate ill-defined areas of enhancement.

Features suggest a primary intermediate to high grade glial tumor. 

The patient went on to have surgery. 


The sections show a moderately cellular astrocytic tumour. Some of the astrocytes contain elongated, angulated and hyperchromatic nuclei. Others show protoplasmic form with rounder nuclei in a loose background. Scattered mitoses are seen. Some of the blood vessels appear hyalinised but there is no evidence of endothelial cell hyperplasia. Small numbers of tumour cells extend into the overlying cortex. No evidence of necrosis is seen. The Ki-67 index is 5-6%.

Final Diagnosis: The features are those of an anaplastic astrocytoma (WHO grade III)

Case Discussion

Fairly typical appearances of an anaplasic astrocytoma with the presence of enhancement in keeping with a grade III tumor. 

Note: IDH mutation status is not provided in this case and according to the current (2016) WHO classification of CNS tumors, this tumor would, therefore, be designated as an anaplastic astrocytoma NOS.

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Case information

rID: 3977
Published: 6th Jul 2008
Last edited: 6th Mar 2020
Inclusion in quiz mode: Included

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