This patient went on to have a stereotactic biopsy which confirmed the diagnosis of a thalamic diffuse astrocytoma, of which low-grade has a much poorer prognosis than similar tumors in other locations.
Today, it would be important to test this tumor for H3 K27M mutation as there is a reasonable chance that it represents a diffuse midline glioma H3 K27M–mutant
Note: IDH mutation and H3 K27M 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.