Immunohistochemical analysis of CD34 expression in salivary gland tumors

Tumor growth depends on angiogenesis which is assessed by measuring the tumor microvessel density (MVD) through CD34 immunostaining. The present study was performed to evaluate the situation of angiogenic activity in salivary gland neoplasms. The possible role of CD34 in progression and invasion of salivary gland tumors is also investigated.

Tissue specimens of 15 pleomorphic adenoma (PA) and 15 malignant salivary gland tumors including mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC) and salivary duct carcinoma (SDC) were immunostained for CD34 protein. The most vascularized areas at low power magnification (hotspots) were selected for vessel counting at ×400 magnification. Then, the mean number of microvessels in three fields within the tumor mass was calculated.

MVD in PA and malignant salivary gland tumors were 10.93 ± 5.95 and 26.46 ± 7.32, respectively. Tumor angiogenesis in PA was much lower than other lesions (P < 0.05). No significant difference was observed between malignant tumors (P > 0.05).

Salivary gland carcinomas demonstrated higher vascular density than benign PA despite of cell types and architecture. The reason for this higher angiogenic activity could be related to metabolic characteristics of malignant cells.