Salivary duct carcinoma :a clinicopathological study of five cases

Purpose To investigate the clinicopathological features,diagnosis,differential diagnosis,therapy and prognosis of salivary duct carcinoma(SDC).Methods The clinical,pathologic and immunohistochemical features were evaluated in five cases of salivary duct carcinoma retrospectively.Results (1)This neoplasm was usually occurred in parotid gland and had a definite predilection for older male patients with mean age of 64.6 years,and the growth of the tumor was usually rather rapid.It was easy to involve peripheral nerves and to metastasize.(2)Salivary duct carcinoma was intraductal nests of dysplastic duct cells that grow in papillary,cribriform and solid configurations.Comedo-type necrosis of the tumor nests was a distinctive feature.In addition,infiltrative growth was usually evident.(3)Immunohistochemistry staining for CK,EMA,CEA,GCDFP-15,c-erbB-2 and p53 were positive expression in most tumor cells and Ki-67 presented a high level proliferation index.The positive expressions of ER,PR were sporadic in some cases,but PSA,CD117,p63,S-100,CD10 and GFAP were all negative expression.(4)Follow-up data suggested that salivary duct carcinoma had a bad prognosis.Three of the five patients with salivary duct carcinoma had recurrence and one of them had metastasis.Conclusions SDC is a high-grade malignant carcinoma among all salivary carcinoma,histopathological changes of salivary duct carcinoma have revealed a variety of similarities to ductal carcinomas in breast.The diagnosis for salivary duct carcinoma depends mainly on the pathological morphology and immunohistochemical expression,and needs to be differentiated from other tumors such as low-grade cribriform cystadenocarcinoma,mucoepidermoid carcinoma,solid adenoid cystic carcinoma,acinic cell carcinoma,papillary cystadenocarcinoma,polymorphous low-grade adenocarcinoma and epithelio-myoepithelial carcinoma.