Objective   This study was conducted to explore the expression and clinical significance of caveolin-1 (Cav-1) in pleomorphic adenoma and paraneoplastic tissues of the parotid gland.

  Methods   Immunohistochemistry was used to detect Cav-1 expression in normal parotid glands, pleomorphic adenoma (0 cm), and paraneoplastic tissues (0.5, 1.0, 1.5, and 2.0 cm from the pleomorphic adenoma).

  Results   Cav-1 was expressed in all normal parotid glands and was mainly expressed in the cytoplasm and plasma membrane of duct systems. Except for six samples 0.5 cm away and one sample 1.0 cm away from the pleomorphic adenoma, Cav-1 was expressed in other adjacent normal tissues, and the expression pattern of Cav-1 was similar to that in normal tissues. In pleomorphic adenoma, Cav-1 only existed in seven samples (accounting for 30.30%) and was prominently expressed in the nucleus. The expression level of Cav-1 was lowest in pleomorphic adenoma and progressively increased with increasing distance from the tumor. A difference in Cav-1 expression was detected between pleomorphic adenoma (0 cm) and paraneoplastic tissues (0.5, 1.0, 1.5, and 2.0 cm from the tumor, P < 0.05). However, no statistical significance existed between paraneoplastic tissues at 1.0, 1.5, and 2.0 cm from the tumor (P> 0.05).

  Conclusion   During the development of pleomorphic adenoma, the expression level of Cav-1 progressively decreased, and translocation of Cav-1 expression from cytoplasm and plasma membrane to nucleus occurred. Cav-1 may have an important role in the progress of pleomorphic adenoma, and the variation in the expression level of Cav-1 may be used as a scientific evidence to determine the safe surgical margin of pleomorphic adenoma.