Immunohistochemical analysis of CD34 expression in benign pleomorphic adenoma according to histopathological subtype

Abstract

Pleomorphic adenoma (PA) is a common tumor which involves both the major and minor salivary glands. Its 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 inPA according to the histopathological subtype. Tissue specimens of (42) PA were sectioned and stained for hematoxylin and eosin, and immune-stained for CD34 protein. The most vascularized areas at low power magnification (hotspots) were selected for vessel counting at (×400) magnification, and the mean number of microvessels in three fields within the tumor mass was calculated. The stroma-rich was the most common subtype, followed by cell-rich and classic. The mean number of the CD34 positive micro vessels in all cases of PAs studied was 7.88±4.381.The mean number of the CD34 positive micro vessels in stroma-rich, cell-rich, and classic types was 11.90±0.867, 2.8±0.941, and 5.4±0.894 respectively. Statistical analysis showed a highly significant difference present between them regarding the MVD (P=0.0001).Salivary gland PA of stroma-rich type showed a higher vascular density than other subtypes, the reason for this higher angiogenic activity could be related to metabolic characteristics, this may add an insight about the type of treatment needed for PA especially the stroma-rich subtype.