Background and objective Salivary duct carcinoma (SDC) is a rare but highly aggressive malignancy. Due to its low incidence, most published data are derived from small retrospective series or case reports, and the optimal diagnostic work-up, prognostic stratification, and treatment algorithms remain poorly defined. This study aimed to investigate the clinical characteristics, pathological features, and treatment strategies for SDC by reviewing the relevant literature. Methods A retrospective analysis was conducted on the clinical and pathological data, histological morphology, immunophenotypic characteristics, and treatment outcomes of seven patients with SDC. Additionally, the relevant literature regarding SDC was also reviewed. Results Among the patients, six were male, and one was female, with a mean age at onset of 58 ± 13.84 years. Most cases occurred in the parotid gland (4/7), followed by the submandibular gland (2/7) and the upper lip mucosa (1/7). The tumors exhibited histological features similar to those of breast cancer, with atypical cells arranged in cribriform, nest-like, and linear patterns. The cells had large nuclei with prominent nucleoli, abundant eosinophilic cytoplasm, and an infiltrative growth pattern. Immunohistochemistry showed positive staining for CKpan, CK8/18, CEA, EMA, AR, 34βE12, and GATA3. The Ki67 proliferation index was high, whereas P63, P40, calponin, S100, SMA, and ER were negative. Some cases showed weak positivity for PR and strong positivity for HER2. Conclusions SDC is a rare but highly aggressive malignant salivary gland tumor characterized by a strong propensity for local invasion and an unfavorable prognosis. It carries a high risk of early local recurrence and both regional and distant metastasis.
Yan et al. (Wed,) studied this question.