5,48] To date, there are no molecular markers to identify potentially, or imminently, anaplastic phenotypes within the diffuse fibrillary astrocytoma group.
4] This important distinction highlights the fact that pilocytic astrocytomas (WHO grade 1) and diffuse fibrillary astrocytomas (WHO grade 2) are fundamentally different entities.
We now demonstrate that [Beta]III is a potential marker of high-grade astrocytomas, and its expression may also define incipient anaplastic phenotypes in diffuse fibrillary astrocytomas.
The cases were grouped into high-grade astrocytomas (consisting of anaplastic astrocytoma, WHO grade 3, and glioblastoma multiforme, WHO grade 4); diffuse fibrillary astrocytomas (including gemistocytic astrocytomas, WHO grade 2); and pilocytic astrocytomas (WHO grade 1).
In diffuse fibrillary astrocytomas, the distribution of [Beta]III immunoreactivity was also substantially less than that in high-grade astrocytomas (MLI, 4%; IQR, 0.
In contrast, [Beta]III immunoreactivity was present to a lesser extent in diffuse fibrillary astrocytomas (WHO grade 2) and was rarely detectable in pilocytic astrocytomas (WHO grade 1).