Biological Behavior of basaloid cells in Oral Carcinoma In-situ

Carcinoma in-situ (CIS) is defined as a true and not-yet invasive neoplasm. Histopathologically, it shows basaloid cell formation known as dysplastic cells mixed with normal differentiated cells in the epithelium. Microscopically, it is difficult to distinguish normal basal cells and carcinomatous cells, also how their biological behavior and how they reach the superficial layer are still unknown. To recognize basaloid cells, their biological behavior in order to carry-out a definitive histopathological diagnose and to know how their possibility replace whole layer of epithelium. Twenty cases of formalin-fixed paraffin sections of hyperplasia, 20 cases mild and 15 cases moderate squamous epithelial dysplasia (SED) as a control, and 15 cases of CIS were subject to Ki-67 immunostaining for proliferating cells and Tunel staining for apoptotic cells. Hyperplasia and mild SED cases expressed Ki-67 located in the parabasal layer, while Ki-67 was extended distributed in basal, parabasal up to superficial layer of moderate SED and CIS. Hyperplasia and mild SED cases showed apoptotic cells located in keratin layer, in contrast moderate SED showed apoptotic cells in prickle layer while CIS, apoptotic cells located in keratin layer and basal layer. The basaloid cells as dysplastic or carcinomatous cells occurred in parabasal layer then expanding to two directions; basal layer and prickle layer. It suggested that apoptotic cells which occurred in prickle layer made basaloid cells able to reach until superficial layer. Therefore, the basaloid cells of CIS replaced whole layer of epithelium but their biological behavior was still definite toward keratinization.