Pleomorphic xanthoastrocytomas (PXA) are rare, low-grade astrocytoma (WHO Grade II) tumors. They occur in young patients and, like many low grade astrocytomas, typically present with epilepsy.

Pleomorphic xanthoastrocytomas are often cortical tumors with a cystic component. MRI imaging shows vivid contrast enhancement. They tend to grow slow, and as such do not show surrounding oedema. A reactive dural involvement expressed by a dural tail sign can be found. Calcifications within the tumor are rare. 

Epidemiology

Pleomorphic xanthoastrocytomas are rare tumors and make up 1% of primary brain neoplasms. They are found in young patients with a peak incidence between 10 and 30 years of age.  

MRI features

T1: T1 weighted imaging shows the solid component to be iso- to hypointense, conform grey matter. The cystic component has a low signal. Over 70% of patiens show leptomeningeal involvement. 

T1 C+ (Gd): The solid component typically enhances vividly. 

T2: T2 imaging has the solid component shown iso- to hyperintense like the grey matter, 

the cystic component containing fluid has a high signal. 

T2 FLAIR: This sequence has cystic areas show hyperintensity relative to cortical spinal fluid due to higher protein contents. There is little to no surrounding vasogenic oedema.