Diagnosis of oligodendroglioma: molecular and classical histological assessment in the twenty-first century

Advances in molecular genetics are currently challenging the traditional morphological categorization of gliomas. Recurrent molecular and cytogenetic aberrations add prognostic and predictive information over and above that provided by standard histomorphological techniques and may influence decisions to re-operate or observe, to deliver radiation or not, or to administer chemotherapy to glioma patients. The importance of routine hematoxylin and eosin (H-E pathological stains cannot be underestimated, especially in resource-poor areas and developing countries where there is likely to be a significant economic opportunity cost for molecular diagnosis services. New research tools for image analyses of histological H-E slides, such as the precise measures of cell area, curvature and nuclear roundness, may provide an increased ability to provide an accurate classification for an inherently subjective process of histological assessment. We discuss the current trends, limitations and impact of molecular classification in this mini review.