Oligodendroglioma. A comparison of two grading systems

Abstract

In order to compare the grading system for oligodendrogliomas described by M.T. Smith (1983) with the conventional grading system according to Kernohan (1938), specimens from 72 patients were graded according to both systems, and survival times of the patients were compared. Survival rates decline in older patients. No interaction between the age of the patient and the degree of the tumor was found. No influence of localization of the tumor on survival was found. Similar to the system of Kernohan, the grading system of Smith distinguishes between only three groups of patients with significantly different survival times. In Smith's Grade A and Kernohan's Grade 1 the longest survivals are found; while in Smith's Grade D and Kernohan's Grade 4 the shortest survivals are found. Smith's Grades B and C as well as Kernohan's Grades 2 and 3 were intermediate with respect to the survival times of the patients and did not significantly differ from each other. With the independently significant features (cell density, pleomorphism, and necrosis) evaluated according to simple on-off scoring, and with the reduction from four grades to three, the grading system according to Smith would provide a simple and good, concise grading system for oligodendrogliomas of the brain.

Valor pronóstico de los marcadores tumorales de proliferación celular y angiogénesis en los oligodendrogliomas

“…Existen diversas clasificaciones histopatológicas de estos tumores, que los dividen en cuatro grados 6,7 , tres grados 8 o preferentemente basado en su pronóstico dos grados 9,10 , lo que coincide con la OMS que los clasifica en bien diferenciados y anaplásicos 11,12 . El objetivo de este estudio es encontrar y valorar por métodos cuantitativos nuevos parámetros que nos permitan establecer el diagnóstico y el pronóstico de los oligodendrogliomas, lo que constituye uno de los retos oncológicos actuales 13 .…”

Oligodendrogliomas: Clinicopathological correlations

“…Soon after its recognition it became clear that in a considerable number of oligodendrogliomas astrocytic cells were encountered, and after the introduction of immunohistochemical stains for glial fibrillary acidic protein, a marker for the astrocytic cell lineage, even more oligodendroglial neoplasms appeared to harbor astrocytic cells [2,3]. Only a limited number of recent studies specifically addresses the problem of how to distinguish oligodendrogliomas from the mixed oligo-astrocytomas by mentioning maximum allowable percentages of astrocytic cells [6][7][8][9]. In recent years immunohistochemical markers specifically reacting with the cells of oligodendrogliomas have been sought but not yet found [4,5].…”

“…Furthermore, there is no consensus regarding the legitimation of individual histopathological features used in grading schemes for oligodendrogliomas. In several recent studies grading schemes consisting of various features have been tested with regard to their predictive power [6,7,9,11,12]. No major differences were apparent between the survival curves resulting from application of the original, rather illdefined scheme of Kernohan, and those obtained by using the schemes later developed by the AFIR or that used by a french-american group (St. AnneMayo) [9,12].…”

“…The St. Anne-Mayo scheme, not exclusively used for oligodendrogliomas, but successfully applied to astrocytomas as well [13], promised to become a good scheme in grading oligodendrogliomas because of encompassing features of undebatable significance [12]. In addition to cell density, nuclear pleomorphism, endothelial abnormality and necrosis, the feature of mitotic index, proven to be a significant parameter, is used in this scheme as well [9,11]. However, application on a group of cases of the Mayo Clinic yielded no more than two (and not three) distinct survival curves [12].…”

Oligodendroglial Tumors

“…Bu kriterler var ya da yok; az ya da çok şeklinde değerlendirilir. Grade A'da tüm kriterler az ya da yoktur; Grade B'de pleomorfizm ve/veya hücre yoğunluğu ve nükleus-sitoplazma oranında artış; Grade C'de pleomorfizm, endoteliyal proliferasyon, nükleus-sitoplazma oranı ve hücre yoğunluğunda artış; ve Grade D'de tüm kriterler vardır ya da çoktur (17). DSÖ sınıflamasında ise oligodendroglioma (Grade II) ve anaplastik oligodendroglioma (Grade III) olmak üzere iki grup mevcuttur.…”