Abstract
Giant cell tumour (GCT) is locally aggressive benign neoplasm of long bones whereas giant cell granulomas; central giant cell granuloma (CGCG) and peripheral giant cell granuloma (PGCG); are tumour-like conditions of the oral cavity. This study aimed to evaluate and compare the immunohistochemical expression of p63 in GCT, CGCG, PGCG and determine whether p63 can be used as a diagnostic, prognostic and differential biomarker between these entities. Histopathologically diagnosed 10 cases of GCT, 20 cases of CGCG and 20 cases of PGCG were subjected to p63 immunohistochemical staining. The percentage of p63-positive cells was semi-quantitatively assessed on the whole section. Intergroup comparison was done using Kruskal-Wallis test and one-way ANOVA. The value p < 0.05 was considered to be statistically significant and value p < 0.01 was considered to be statistically highly significant. p63 immunoexpression was seen in 100% (10/10) cases of GCT whereas CGCG and PGCG revealed the complete absence of p63 immunopositivity. These results showed a highly significant difference in p63 expression between GCT, CGCG and PGCG (p < 0.01). No difference was noted between CGCG and PGCG. GCT is a distinct entity when compared with CGCG and PGCG. Even aggressive CGCG also did not show p63 immunopositivity, so it is not a prognostic marker. Also, p63 cannot differentiate between CGCG and PGCG.