Case 014

History/Physical

History/Physical:

55-year-old left-handed male.

Progressive headache and personality change over three months.

There is a large ill-defined mass in the left frontal lobe (*). The mass is intra-axial as it is surrounded by cortex (arrowheads). This has curvilinear T1 high signal at the margin (arrows), which could be from calcification or hemosiderin.

Some regions within the mass have enhancement (arrowhead).

The mass is heterogeneous on T2 (*). The curvilinear low signal corresponds with the intrinsic T1 high signal, and could be calcification or hemosiderin (arrowhead). There is T2 high signal at the margin (arrow).

There is over 2cm of subfalcine herniation.

Diagnosis: Oligodendroglioma, IDH-mutant and 1p/19q codeleted, grade 3

Moderately cellular neoplasm with prominent microcysts and fine, branched vessels.

Tumour cells have rounded nuclei, little cytoplasm and variably prominent perinuclear halos.

Nuclear pleomorphism and mitotic activity (arrow). Random high power field counts revealed > 2.5 mitoses/mm².

Apoptosis (arrow), atypia, minigemistocytes (arrowhead) and early endothelial hyperplasia (*).

Moderately high proliferative activity.

Largely GFAP-negative tumour cells on a background of reactive (GFAP-positive) astrocytes.

Nuclear ATRX expression is retained (wild-type).

Expression of mutated IDH-1 (R132H). (1p/19q codeletion detected by FISH)