Anaplastic astrocytoma IDH wildtype (pineal region)

Case contributed by A.Prof Frank Gaillard

Presentation

2 weeks of worsening headaches and blurred vision

Patient Data

Age: 45 years
Gender: Female

There is a mass in the quadrigeminal plate cistern which is homogeneously mildly T2 hyper- and T1 hypointense to grey matter which demonstrates avid heterogeneous contrast enhancement. There is abnormal signal also extending into the thalami, more marked on the right. It diffusion restricts. 

There is increased blood volume in the lesion. The MRS shows increased choline-creatine ratio with reduced NAA peak in keeping with a high-grade tumour trace.

There is obstruction of the cerebral aqueduct with hydrocephalus involving the lateral and third ventricles. Mild periventricular T2 hyperintensity suggests a degree of transependymal oedema.

The patient went on to have a craniotomy and excision of the tumour. The mass was inseparable from both the pineal gland and the left thalamus. A clear site of origin could not be established. 

Pathology

Histology

MICROSCOPIC DESCRIPTION: Paraffin sections show a densely hypercellular glial tumour with strong immunostaining for GFAP and nestin indicating astrocytic differentiation. There is moderate nuclear and cellular pleomorphism.  Moderate numbers of mitotic figures are identified. Vessels are prominent throughout the tumour. These are enclosed within sleeves of fibrous tissue and do not show endothelial cell hyperplasia. No necrosis is seen. Moderate numbers of cells show strong immunostaining for synaptophysin. These are interpreted as incorporated pineocytes.  No immunostaining for NeuN or IDH-1 is seen.

Interpase FISH: 

  • 1p36 - No loss detected 
  • 19q13 - No loss detected

FINAL DIAGNOSIS: Anaplastic astrocytoma (WHO Grade III)

Note: Although this tumour is entirely consistent with IDH wild-type molecular subtype, strictly speaking, to conclusively establish this, IDH would need to be sequenced to ensure that a non-IDH1 R132H mutation was present. In practice, an IDH1 R132H negative tumour in an individual over 55-years-of-age makes the possibility of this being IDH mutant remote (<1%), and sequencing is not felt to be necessary by many institutions, and not recommended by the WHO classification of CNS tumours (2016). 

Case Discussion

As is the case elsewhere, one must not focus exclusively on lesions typical of a specific location. In this instance, astrocytomas of the pineal or nearby parenchyma must be considered when a pineal region mass is found. 

PlayAdd to Share

Case information

rID: 22667
Case created: 14th Apr 2013
Last edited: 22nd Jun 2017
Tag: pineal
Inclusion in quiz mode: Included

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.