Salivary duct carcinoma of the submandibular gland presenting a diagnostic challenge: A case report

BACKGROUND: Salivary duct carcinoma (SDC) is a rare, extremely aggressive malignancy that arises in the submandibular gland. It can metastasize locally early and therefore is an important differential diagnosis of metastatic disease in cervical lymph nodes or specific lymphadenitis such as tuberculous cervical lymphadenitis. CASE SUMMARY: We report a case of SDC in the submandibular gland that presented diagnostic difficulty. The lesion was coincidentally discovered through examination of the radiolucent area of the maxilla. Imaging failed to confirm the possibility of specific inflammation, leading us to execute an open biopsy to verify the diagnosis. The surgical specimen showed that the submandibular gland was primarily replaced with a calcified body. Following histological analysis and confirmation, we performed surgical resection, radiotherapy, and various chemotherapies. CONCLUSION: Radiographic imaging characteristics of lymph node metastases of salivary gland cancer, especially of SDC, may resemble other cervical lymphadenitis; calcification at the submandibular gland is the landmark of SDC occurring at the subman-dibular gland.