Anaplastic astrocytoma

Note the intrinsic high T1 signal secondary to calcification, with little enhancement.

MICROSCOPIC DESCRIPTION:

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%.
The features are those of anaplastic astrocytoma.

DIAGNOSIS:

Brain tumour: Anaplastic astrocytoma (WHO Grade III).