title: Evaluation of c-kit protein (CD117) expression in common salivary gland neoplasms.
abstract: BACKGROUND
  Adenoid cystic carcinoma (AdCC) is a malignant salivary gland neoplasm with poor long-term prognosis. Differentiating between AdCC and other salivary gland neoplasms can be a diagnostic challenge, particularly in examining tissues obtained from small incisional biopsies.
  
  
  OBJECTIVE
  The aim of this study was to evaluate c-kit expression in four common benign and malignant salivary gland neoplasms.
  
  
  METHODS
  Immunohistochemical techniques were used to analyze the level of c-kit expression in normal salivary gland (n = 10) and four different types of salivary gland tumors: Pleomorphic adenoma (PA) (n = 17), AdCC (n = 9), polymorphous low-grade adenocarcinoma (PLGA) (n = 4) and mucoepidermoid carcinoma (MEC) (n = 6). Samples were immunostained using monoclonal antibody against c-kit.
  
  
  RESULTS
  The immunoreactivity for c-kit was found in all cases of AdCC, PLGA and MEC and majority of PAs. Positive reactivity was observed in more than 50% of the tumor cells of AdCC and less than 50% in PLGA. PA did not show strong immunostaining and c-kit was predominantly localized to the cell membrane. Furthermore, the difference in the expression of c-kit between the benign and malignant neoplasms was not statistically significant.
  
  
  CONCLUSIONS
  CD117 expression itself cannot be used as a marker in differential diagnosis of salivary gland neoplasms. However, the percentage of the CD117 immunoreactive cells and the staining intensities appeared to be important factors in distinguishing AdCC from PLGA and PA.
authors.affiliation: Department of Oral and Maxillofacial Pathology, Dental Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Jahanshah
authors.initials: J
authors.lastname: Salehinejad
authors.affiliation: Department of Oral and Maxillofacial Pathology, Oral and Maxillofacial Diseases Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Mohtasham
authors.affiliation: Department of Oral and Maxillofacial Radiology, Dental Research Centre, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Bagherpour
authors.affiliation: Department of Oral and Maxillofacial Pathology, School of Dentistry, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Abbaszadeh-Bidokhty
authors.affiliation: Department of Oral Medicine, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ala
authors.initials: A
authors.lastname: Ghazi
keywords: Adenoid cystic carcinoma; C-kit proto-oncogene; salivary gland neoplasms