Thalamic pleomorphic xanthoastrocytoma central nervous system World Health Organization grade 3

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor. According to the 2021 World Health Organization (WHO) classification of central nervous system (CNS) tumors, PXAs with 5 or more mitoses per 10 high-power fields are classified as CNS WHO grade 3. Imaging findings of PXA CNS WHO grade 3 have rarely been reported, and thalamic cases are particularly uncommon. We present a case of thalamic PXA CNS WHO grade 3. A 71-year-old male presented with progressive right hemiparesis over three months. Magnetic resonance imaging (MRI) revealed a mass lesion in the left thalamus. Due to rapid tumor growth causing obstructive hydrocephalus, he underwent urgent craniotomy for tumor resection. Histopathology confirmed a PXA CNS WHO grade 3. Postoperatively, the patient received 54 Gy of radiation therapy in 27 fractions. His right hemiparesis persisted. He was subsequently transferred to a rehabilitation hospital.