When histology tells a different story: salivary duct carcinoma in disguise

Salivary duct carcinoma (SDC) is a rare, high-grade malignancy known for its aggressive clinical behaviour and histological resemblance to ductal carcinoma of the breast. It predominantly arises in the major salivary glands and typically affects older males. This case report highlights an unusual presentation of SDC originating from the minor salivary glands of the buccal mucosa in a 52-year-old male with a notable history of chronic tobacco use. The patient presented with a painless intraoral mass that was rapidly increasing in size and was initially presumed to be carcinoma of the buccal mucosa. Histopathological analysis revealed solid nests and islands of malignant epithelial cells with areas of comedonecrosis, displaying architectural patterns characteristic of SDC. Immunohistochemically, the tumor cells showed CK7 positivity and were negative for CK20 and myoepithelial markers, confirming the diagnosis. This rare case underscores the importance of considering SDC in the differential diagnosis of aggressive intraoral neoplasms, especially in atypical locations such as the minor salivary glands.