Protoplasmic astrocytoma with multifocal involvement: case report and radiological findings

Protoplasmic astrocytomas are a poorly characterized and extremely rare subtype of astrocytoma. We describe the CT, MR and ¹⁸F-fludeoxyglucose positron emission tomography (FDG-PET) findings of a multifocal protoplasmic astrocytoma in a 29-year-old male with neurological deficits. He was initially diagnosed with neurosarcoidosis based on imaging. MRI demonstrated intraparenchymal lesions involving the right temporal lobe and cerebellum. These appeared as extremely hyperintense signals on T ₂ weighted imaging and as homogeneous enhancements with a small non-enhancing cystic component on contrast-enhanced MR. Diffuse post-contrast enhancement of the craniospinal meninges was also noted. Post-radiation therapy PET-CT demonstrated a highly FDG-avid tumour in the right temporal lobe and left cerebellum. To our knowledge, a multifocal form of protoplasmic astrocytoma in an adult patient has not been previously described.