ERBB2 and carcinoma: The positive rate in salivary duct carcinoma in situ was 23% (CI 95%: 11.9–39.5%), the expression rate of HER2/neu in carcinoma ex pleomorphic adenoma (CXPA) was 55% (CI 95%: 37.4–71.1%), and the pooled positive rate of for SDC was 41% (CI 95%: 34.8–47.7%).