Revision 5 for 'Modified Ringertz grading system for diffuse astrocytomas'All Revisions
Modified Ringertz grading system for diffuse astrocytomas
The Modified Ringertz grading system is one of the more frequently used grading systems for diffuse astrocytomas, only second to the WHO grading system. Unlike the WHO grading system and St Anne-Mayo grading system (also known as the Dumas-Duport grading sustem) which divide astrocytomas into 4 grades, the Ringertz grading system only has 3 grades, and only applies to diffuse astrocytomas (i.e. not WHO grade 1 tumors such as pilocytic astrocytomas or subependymal giant cell astrocytomas) 1.
As such there is a rough equivalence between WHO II - IV and modified Ringertz I - III, although there are some differences in the criteria required to fulfill various grades.
The modified Ringertz grading system is as follows 2:
- grade 1 = astrocytoma
- roughly equivalent to WHO grade II
- mild hypercellularity
- mild nuclear atypia (nuclear enlargement, hyperchromasia, pleomorphism)
- rare mitotic figures
- grade 2 = anaplastic astrocytoma
- roughly equivalent to WHO grade III
- more cellular than grade 2
- more nuclear atypia
- more mitotic figures
- endothelial proliferation (note this is a WHO grade IV feature)
- grade 3 = glioblastoma multiforme
- roughly equivalent to WHO grade IV
- presence of geographic necrosis +/- surrounding pseduopalisading tumor cells
History and etymology
Ringertz originally proposed the grading system in 1950 4.