Presentation
Transient vision loss.
Patient Data
Left sided periventricular mass, which is hyperdense to brain parenchyma. Few internal low density components. Dilatation of the left temporal horn with periventricular hypoattenuation most likely from obstruction and CSF trapping.
Left temporoparietal periventricular mass demonstrating enhancement, which is fairly homogeneous with a few non-enhancing low density components.
Left temporal lob intra-axial irregular enhancing mass, which is heterogeneous, containing areas of intrinsic T1 hyperintensity and susceptibility blooming, indicating hemorrhage. Irregular rind of enhancing tissue peripherally, with lack of enhancement centrally. Linear enhancement is also demonstrated lining the occipital horn of the left lateral ventricle, indicative of subependymal spread.
Left ventricular trigone obstruction with dilatation of the left temporal and occipital horns.
MR perfusion shows elevated relative CBV correspond to enhancing tumor. The mass also demonstrates significant diffusion restriction (ADC values <600 x 10^6 mm2/sec). Additionally increased T2 signal change is seen involving the mesial temporal lobe on the right.
Histopathology
MICROSCOPIC DESCRIPTION: The sections show features of a densely cellular astrocytic tumor. The tumor cells have elongated, angulated and hyperchromatic nuclei. Scattered mitotic figures are identified. There are foci of microvascular proliferation. Necrosis is absent. There is no evidence of oligodendroglial component. No lymphoma is seen. The features are those of glioblastoma. The tumor cells are p53 positive. The topoisomerase index is about 10%. IDH1-R132H immunostain is negative. MGMT is also negative (likely methylated). ATRX shows no loss of staining (non-mutated).
DIAGNOSIS: Left temporal periventricular tumor: Glioblastoma (WHO Grade IV), IDH-wildtype.
Case Discussion
On imaging, a periventricular component can suggest a lymphoma but there is internal hypodensity suggesting necrosis on the CT and further evidence of hemorrhage on the MRI. Both of these are not features of lymphoma but more of a high-grade glial tumor. This is also not a typical pattern for metastasis, which is the only other possible differential.