Tyrosine kinase B expression correlates with perineural invasion in salivary adenoid cystic carcinoma.

Objective Objective To observe the expression of TrkB in salivary adenoid cystic carcinoma(ACC), and to evaluate the relationship between TrkB and perineural invasion in ACC.Methods TrkB was examined in 28 salivary ACC , 3 normal parotid glands, 3 normal submandibular gland, 3 sublingual gland and 5 acinic cell carcinoma tissue samples by immunohistochemical SABC method and image analysis.Results In pathological study, the rate of perineural invasion in ACC was 46.4%(13/28). TrkB was positive in 92.8%(26/28) of ACC, and TrkB expression in group with perineural invasion was significantly higher than the one without perineural invasion (P=0.001). TrkB showed positive in ductule cells of normal big salivary gland but not in acinic cell carcinoma.Conclusion TrkB may be considered as a biological marker for perineural invasion in salivary ACC. Enhanced expression of TrkB may contribute to perineural invasion in salivary ACC.