Cite this page: Abdelzaher, E. Diffuse astrocytoma NOS. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumordiffuseastrocytomaNOS.html. Accessed May 27th, 2018.
Definition / general
- Tumor morphologically conforming with diffuse astrocytoma but in which IDH testing is not available or cannot be fully performed
- Modifier "not otherwise specified" (NOS) does not refer to a specific entity; it simply indicates that the case requires additional molecular workup (Acta Neuropathol 2016;131:803)
- Full IDH evaluation requires IDH sequencing for IDH1 codon 132 and IDH2 codon 172 mutations following a negative IDH1-R132H immunohistochemistry (Acta Neuropathol 2016;131:803)