Oligodendroglial neoplasms: Current concepts, misconceptions, and folklore

Given current prognostic and therapeutic implications, the accurate classif ication and grading of oligodendroglial neoplasms has become critical. Howe ver, the prevalence of morphologically ambiguous gliomas, subjective histol ogic criteria, personal biases, oligodendroglioma mimics, and the lack of s pecific oligodendroglioma markers has led to high interobserver variability and created a contentious problem encountered daily in active surgical neu ropathology practices. Since histologic assessment is still a powerful prog nosticator, it appropriately remains the diagnostic gold standard. However, recent efforts have focused on identifying the most reproducible and clini cally relevant criteria, standardizing classification and grading: schemes, and searching for useful ancillary biologic and genetic markers capable of further stratifying an otherwise heterogenous patient population. This pap er reviews the morphologic and genetic spectrum of oligodendroglial neoplas ms, recent diagnostic and prognostic developments, and potential future dir ections.