An Immunohistochemical Study Showing Ki-67 as an Analytical Marker in Oral Malignant and Premalignant Lesions

INTRODUCTION: Ki-67 is a nuclear protein. It is a proliferation marker that has an essential function in tumorigenesis due to its positive connection with tumor expansion. AIM: The aim of this study was to evaluate the articulation of Ki‑67 as prognostic marker in various grades of oral epithelial dysplasia (OED) and in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: A total of 100 histologically affirmed samples of normal oral mucosa (NOM), OED, and OSCC were divided into three groups—Group I (10 samples of normal oral mucosa), Group II (45 samples of OED), Group III (45 samples of OSCC). Routine hematoxylin and eosin and immunohistochemical staining with Ki-67 monoclonal antibody were carried out in all the samples. RESULTS: Within Group I, articulation of Ki-67 was constrained to the basal layers. In Group II, cells showing positive expression of Ki-67 were available in the basal, suprabasal, and spinous layers. Cells showing positive expression of Ki-67 among well-differentiated OSCC were presented mainly in the periphery of the tumor nests; in moderately differentiated OSCC, cells were located in both peripheral and part of a center of the tumor nests; and in most cases of poorly differentiated OSCC, cells were diffused. Statistically significant difference in positive expression of Ki-67 was appreciated between three groups. CONCLUSION: Ki-67 antigen may perhaps be used as a marker for the histological reviewing of OED and OSCC. With the increase in the severity of OED, cells showing positive expression of Ki-67 also increased.