Immunohistochemical evaluation with Ki-67: An application to salivary gland tumours

Abstract

Using Ki-67, a monoclonal antibody, the proliferating capacity of 15 salivary gland tumours, including nine pleomorphic adenomas, four adenoid cystic carcinomas, one mucoepidermoid carcinoma and one acinic cell carcinoma was determined immunohistochemically, using normal salivary gland tissue as a control. The frequency of Ki-67 positive cells was 4.7 per cent in the normal salivary gland and one per cent in pleomorphic adenomas, whereas the average frequency in malignant tumours was 18.3 per cent. Among adenoid cystic carcinomas, the frequency was related to the morphological type; the solid sub-type had the highest frequency of Ki-67-positive cells. As this sub-type is recognized as the most aggressive of these tumours, this technique has the potential of providing an early indication of the clinical behaviour of a tumour.

Cell proliferation in salivary gland adenocarcinomas with myoepithelial participation

“…However, all these studies [14,16,19,22] like ours, demonstrate very consistently that solid adenoid cystic carcinoma has proliferation index values double those of more differentiated, cribriform and/or tubular forms.…”

“…Previous studies on salivary gland tumour proliferation have mostly been restricted to the group of adenoid cystic carcinomas and have used different methodologies, namely S-phase cytometric determination [16], Ki-67/MIB1 [14,19] and PCNA immunocytochemistry [22], which biases the comparison of the different results. However, all these studies [14,16,19,22] like ours, demonstrate very consistently that solid adenoid cystic carcinoma has proliferation index values double those of more differentiated, cribriform and/or tubular forms.…”

“…Information on the proliferation characteristics of normal and neoplastic human salivary gland tissues is scarce, especially in salivary gland carcinomas that express dual differentiation [3,5,14,16,19,20,22]. This group of tumours is formed by cells that exhibit both epithelial and myoepithelial phenotypes and includes four entities: adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, polymorphous low-grade adenocarcinoma and basal cell adenocarcinoma [13,18].…”

Benign and Malignant Oncocytoma of the Salivary Glands with an Immunohistochemical Evaluation of Ki-67

“…We tried to distinguish benign oncocytoma from malignant oncocytoma with Ki-67 immunostain, and there was a higher frequency of Ki-67-positive cells in malignant oncocytoma. Murakami et al [5] demonstrated that the frequency of Ki-67-positive cells was significantly higher in malignant salivary gland tumors (adenoid cystic carcinomas, mucoepidermoid carcinoma and acinic cell carcinoma) compared to that in benign tumors (pleomorphic adenomas) of the salivary gland. Skalova et al [6,7] reported that cell proliferation activity in acinic cell carcinomas and mucoepidermoid carcinomas in the salivary glands, assessed with Ki-67 staining, represented a significant prognostic factor.…”

“…Ki-67 is a nuclear protein expressed in proliferating cells, except in those in the G0 period of the cell cycle [4]. The close correlation between the frequency of Ki-67-positive cells and the grade of malignancy has been well established in various subtypes of salivary gland tumors, with the exception of oncocytoma [5][6][7][8].…”