I have noticed a lot of chatter on the SCTA Facebook page related to diagnoses and WHO classifications of tumors. I know that this is an important issue for those of us who have been given a SCT diagnosis, so I started looking for resources related to this topic. One of the best resources I have found in terms of explaining the differences in the WHO grades is:
Of everything presented in the article, I think the following paragraph was the most helpful:
Grade I applies to lesions with low proliferative potential and the possibility of cure following surgical resection alone. Neoplasms designated grade II are generally infiltrative in nature and, despite low-level proliferative activity, often recur. Some type II tumours tend to progress to higher grades of malignancy, for example, low-grade diffuse astrocytomas that transform to anaplastic astrocytoma and glioblastoma. Similar transformation occurs in oligodendroglioma and oligoastrocytomas. The designation WHO grade III is generally reserved for lesions with histological evidence of malignancy, including nuclear atypia and brisk mitotic activity. In most settings, patients with grade III tumours receive adjuvant radiation and/or chemotherapy. The designation WHO grade IV is assigned to cytologically malignant, mitotically active, necrosis-prone neoplasms typically associated with rapid pre- and postoperative disease evolution and a fatal outcome. Examples of grade IV neoplasms include glioblastoma, most embryonal neoplasms and many sarcomas as well. Widespread infiltration of surrounding tissue and a propensity for craniospinal dissemination characterize some grade IV neoplasms.
My own tumor was given a WHO grade I. Based on the information in this article, my surgeon’s approach to the tumor makes complete sense. Although the tumor has the potential to recur, he believes he achieved a complete resection of the tumor. He is having me return every three months to make sure there are no signs of recurrence, but he is very optimistic when my long term prognosis is considered. Hopefully this article will help other SCT survivors understand the implications of WHO grading.
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A, Scheithauer BW, Kleihues P (2007) The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 114(2):97–109
Disclaimer: I am not a doctor. I do not have any training in this area. I am just sharing my personal observations.