ObjectiveTo detect the expression of endothelial cell specific molecule (ESM1) in adenoid cystic carcinoma (ACC) and to analyze the correlations between the expression of ESM1 and clinicopathological features of ACC.MethodsClinicopathological data of patients suffering from ACC diagnosed in our hospital from Jan. 2004 to Jan. 2015 were analyzed retrospectively. The expression of ESM1 in 60 ACC specimens and 20 of paracancerous tissue was detected by Envision immunohistochemical method. The results were analyzed with IPP 6.0 and SPSS 17.0. ResultsCompared to the weakly positive expression in paracancerous tissues, the expression of ESM1 in ACC tissues was strongly positive, especially in those with recurrence, metastasis, perineural invasion (PNI) and at advanced clinical stage. The expression differences between those with and without recurrence, metastasis, PNI, as well as between early and advanced clinical stage were statistically significant (P=0.001, 0.024, 0.010 and 0.026, respectively). ConclusionThe expression of ESM1 is positively correlated with the recurrence, metastasis, nerve invasion and clinical stages of ACC, that is, the expression of ESM1 is correlated with the malignancy of ACC, which may provide evidence for the molecular targeting therapy of this tumor.