Discrimination of normal from pre-malignant cervical tissue by Raman mapping of de-paraffinized histological tissue sections

The authors present Raman cluster mapping of de-paraffinized normal cervical tissue and demonstrate the ability of this approach to differentiate between normal squamous epithelium and cervical intraepithelial neoplasia (CIN). Multivariate analysis was performed by hierarchical cluster analysis (HCA) of the Raman spectra associated with the different tissue types and Raman maps were generated using the resultant clusters. Using normal cervical tissue, squamous epithelium and the epithelial-stromal interface, a muscular artery and endocervical glands were successfully mapped. Analysis of a tissue section containing a cervical intraepithelial neoplasia (CIN) grade 2 lesion adjacent to normal squamous epithelium demonstrated that the CIN lesion clustered predominantly with the basal epithelial cells of normal epithelium and allowed visual discrimination of these areas using the Raman map. These findings suggest that Raman mapping has the potential to provide images that are useful for disease diagnosis. In particular, the discrimination between normal cervical squamous epithelium and CIN is of relevance to cervical screening pathology.