Magnetic resonance imaging and histopathological features of a butterfly glioblastoma in a two-year old dog.

Introduction / Purpose: This report describes the clinical, MRI and post-mortem findings of a unique, rarely reported presentation of a butterfly glioblastoma in a young dog.
Methods:
A two-year-old female neutered Cockapoo was presented with lethargy and abnormal neurological episodes including obtunded mentation and behaviour, as well as generalised epileptic seizures. A brain MRI was performed using a 1.5T scanner, which included T2-weighted, T1-weighted pre- and postcontrast, T2 FLAIR, T2-GE and DWI sequences. The patient was euthanised, and post-mortem examination and histopathology were performed.
Results:
The MRI showed a bi-hemispheric, intra-axial, contrast-enhancing mass lesion within the forebrain that was extending across the corpus callosum and was mimicking an intraventricular bilateral symmetrical lesion. Post-mortem examination demonstrated a symmetrically effacing, infiltrative neoplasm that was replacing approximately 75% of the neuropil at the centre of the forebrain and midbrain. Histopathological assessment of this lesion was consistent with a high-grade astrocytoma such as glioblastoma multiforme. Given the bi-hemispheric, wing-like appearance on MRI and histopathological features, this lesion has been further classified as a butterfly glioblastoma.
Discussion / Conclusion:
The MRI and histopathological findings of this case are consistent with a butterfly glioblastoma, which is a rare condition in human and veterinary medicine, and the first case reported in a young dog. Butterfly glioblastoma, although rare, should be considered in bilateral symmetrical lesions that could mimic an intraventricular neoplasia.