[Clinicopathological analysis of 40 cases of salivary duct carcinoma]

Objective: To investigate the clinical manifestations and pathological changes of salivary duct carcinoma (SDC) and the relationship between them, so as to provide reference for the diagnosis of SDC. Methods: In this retrospective analysis 40 cases of SDC diagnosed from January 2012 to August 2018 in the Department of Pathology of the First Affiliated Hospital of Zhengzhou University were enrolled and the clinical and pathological characteristics were analyzed, 29 were male and 11 were female, the ratio of male to female was 2.64∶1, the median age was 59.0 years, the average course of disease was 3.5 years. The reported cases of SDC were reviewed and compared with patients of this study. Results: Among the 40 patients, 24 cases occurred in parotid gland, 9 cases in submandibular gland and 7 cases in small salivary glands; 24 cases had cancer cell infiltration and invasion of adjacent tissues, 11 cases had lymph node metastasis and 9 cases had distant metastasis at the time of diagnosis. Pathological results showed that 27 cases belonged to primary salivary duct carcinoma, 13 cases belonged to malignant transformation of pleomorphic adenoma; 10 cases invaded local nerve, 22 cases invaded glandular lobules and ducts. Immunohistochemical results showed that 33 cases were positive for androgen receptor, 27 cases were positive for cytokeratin-7, 22 cases were positive for human epidermal growth factor receptor-2, 8 cases were positive for gross cyst disease fluid protein 15. The proliferation index of nuclear antigen Ki-67 ranged from 10% to 90%. Among them 18 cases were over 50% and 22 cases were below 50%. Conclusions: Salivary duct carcinoma is a rare and highly malignant tumor of the salivary gland. Accurate pathological diagnosis is helpful to inhibit the early local recurrence, distant metastasis and improve survival rate of salivary duct carcinoma.