Histopathological Classification & Grading System Of OSCC

Histological grading has long been used to predict clinical behaviour and the prognosis of OSCCs. It was first introduced in 1920 by Broders based on the proportion of differentiated cells to undifferentiated / anaplastic cells within the entire tumour cell population and graded as highly/well, moderately, poorly differentiated and undifferentiated tumours. Bryne et al modified the Anneroth grading system, hypothesizing that the morphological features within the invasive fronts are important in prediction of a tumour's clinical behaviour and prognosis. His hypothesis was that the tumour cells at the invasive fronts of the tumour are likely to be those which metastasize, so that their features are likely to be more predictive than those in the bulk of the tumour. Based on various molecular features, later studies also highlighted that the exclusion of central and superficial parts of tumours would increase the prognostic power of any grading system as these latter areas did not represent the metastasizing phenotype. The modified malignancy grading system of Bryne et al. graded only the most anaplastic areas at the invasive fronts of the tumours.