Crystal violet stain as a selective stain for the assessment of mitotic figures in oral epithelial dysplasia and oral squamous cell carcinoma

Abstract

Assessment of mitotic figures (MFs) is routinely practiced as prognostic indicator in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), but identification of MFs poses a problem in terms of staining characteristics. To evaluate effectiveness of crystal violet stain for staining of MFs and its comparison with hematoxylin and eosin (H and E) stain. Study sample includes archival tissues embedded in paraffin blocks diagnosed as OED (n = 30) and OSCC (n = 30). The control group comprised of tissue specimen from oral mucosa of healthy volunteers (n = 30). Two serial sections of each tissue specimen were stained separately with H and E stain and 1% crystal violet stain. The stained sections were observed under microscope for identification and counting of MFs. Data obtained was statistically analyzed by using the Man-Whitney U test. A significant increase in number of MFs was observed in OED and OSCC in comparison with normal oral mucosa. There was a highly significant increase in number of MFs in crystal violet stained tissue sections when compared with H and E stain. Metaphase is the most commonly observed phase of mitosis in crystal violet stain when compared with H and E stain for all three groups. Crystal violet stain can be considered as selective stain for mitotic figures.