A Rare Case of Adult-Onset Diffuse Midline Glioma

A BSTRACT Diffuse midline glioma is a WHO grade IV tumor of the central nervous system (CNS). The most common sites from which diffuse midline glioma arises are the spinal cord, brain stem, thalamus, and rarely cerebellum. This is a highly aggressive and rare tumor of CNS, more common in the pediatric population. MRI brain lesions are T1-weighted (T1W) image hypointense and T2-weighted (T2W) image hyperintense and may show subtle contrast enhancement, with a more exophytic component and adjacent structure infiltration. Here, we report a case of 30 years old male who presented with symptoms of headache since 15 days, associated with one episode of transient blurring of vision and imbalance while walking. On examination, bilateral early papilledema and subtle bilateral cerebellar signs were present. MRI brain study showed multiple rounds to oval lesions in the corpus callosum, left thalamus, left periventricular region, vermis, and right cerebellar hemisphere, with low apparent diffusion coefficient and diffusion restriction and no blooming on gradient echo sequences images. Initially, no postcontrast enhancement was seen. Later on, the patient’s condition deteriorated despite intravenous steroids and anti-epileptics. On repeat, MRI contrast showed subtle contrast enhancement with an increase in the size of lesions. Stereotactic biopsy from the corpus callosum lesion was done. Histopathology showed diffuse midline glioma WHO grade IV tumor. Even after receiving chemotherapy and radiotherapy, patient succumbed within 4 months of diagnosis. This is a case of adult-onset diffuse midline glioma with a very atypical lesion on the MRI brain as compared to prior studies where the midline structure is more commonly involved.