ERBB2 and mucoepidermoid carcinoma: When the 15 HER2-positive patients were investigated histopathologically, 5 patients had SDC, 6 had CXPA carcinoma ex pleomorphic adenoma, and 4 patients had squamous cell carcinoma, mucoepidermoid carcinoma, basal cell carcinoma, or adenocarcinoma (NOS).