Fig. 2

The pathological results of the exophytic nasal papilloma (hematoxylin and eosin staining). A The tissue section under a microscope, × 40. The tumor grew with the manifestation of the papillary mass and was covered by the squamous epithelium (the scope within the red box illustrates the specimen under key observation). B Enlarged × 40, an axis of fibrous connective tissue is visible in the center (as shown by the red arrow). C Enlarged × 200, the basal cells are visible in the fiber axis with a neat arrangement (as shown by the red arrow). The spinous cells are also visible with a disordered arrangement and mild dysplasia (as shown by the yellow arrow). D Enlarged × 400, it can be seen that the darker cells with connected nuclei are the nuclear divisions of the epithelial spinous cells (as shown by the red arrow)