Diffuse astrocytoma NOS ("protoplasmic")


This case was histologically proven to be a protoplasmic astrocytoma, which is one of the variants of diffuse low grade astrocytomas

This tumor tends to occur in young adults with a reported predilection to frontal and temporal lobe. On imaging, they typically present as a cortical mass with a very high signal on T2 that characteristically suppress on FLAIR sequence (represent the areas with abundant microcystic change). 

Note: Until recently, protoplasmic astrocytomas were classified as a subtype low-grade astrocytoma, however, in the latest (2016) update to WHO classification of CNS tumors, protoplasmic astrocytomas no longer exists as a distinct entity, but rather are considered as a pattern of certain gliomas, requiring IDH +/- 1p19q status for classification. 

Note: IDH mutation status is not provided in this case and according to the current (2016) WHO classification of CNS tumors, this tumor would, therefore, be designated as a diffuse astrocytoma NOS.