Anaplastic astrocytoma NOS

Case contributed by Frank Gaillard
Diagnosis certain


Middle aged patient presenting with a seizure.

Patient Data

Age: Adult

Note: This case has been tagged as "legacy" as it no longer meets image preparation and/or other case publication guidelines.


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 tumor. 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 tumor 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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