Presentation
Seizure.
Patient Data
There is a bad-defined expansile lesion in the left frontal lobe with signs of cortical involvement and local vasogenic edema. Further investigation with MRI is mandatory for a better characterization of this finding.
Ventricular system and cisternal spaces appear normal.
There is no shift of the midline structures.
There is a left frontal lobe tumor characterized by focal cortical involvement in the inferior frontal gyrus associated with an extensive area of high T2 signal in the adjacent white matter which slightly and partially suppress on FLAIR , extending partially to the adjacent insula and middle frontal gyrus. No contrast enhancement is observed. Mild areas of restricted diffusion are observed within the tumor.
Ventricular system and cisternal spaces appear normal. There is no shift of the midline structures. The visualized orbits, paranasal sinuses and calvarium appear unremarkable.
Case Discussion
This case represents a left frontal solid tumor involving the cortex and with features suggesting a low-grade glioma. The tumor was resected and confirmed as a protoplasmic astrocytoma.
Note: Until recently, protoplasmic astrocytomas were classified as a subtype low-grade astrocytoma, however, in the latest (2016) update to WHO classification of CNS tumors, protoplasmic astrocytomas no longer exists as a distinct entity, but rather are considered as a pattern of certain gliomas, requiring IDH +/- 1p19q status for classification.
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 a diffuse astrocytoma NOS.