Rapidly growing primary squamous cell carcinoma of the submandibular gland: A rare case and literature review

Primary squamous cell carcinoma (PSCC) is rare and aggressive in major salivary gland tumors, especially in the submandibular gland. In this report, we present a rare case of PSCC of the submandibular gland in an 81-year-old man, who is the oldest reported person with this disease. He was diagnosed with PSCC on the basis of clinical and imaging examinations and differential diagnosis with other salivary gland tumors through immunohistochemical staining and fluorescence in-situ hybridization. He underwent wide local excision of the submandibular gland with partial mandibulectomy and ipsilateral modified radical neck dissection. The patient subsequently received adjuvant radiotherapy and immunotherapy but died due to multiple pulmonary metastases 22 months after surgery. The features and findings of this case were compared with those of previously reported cases (n = 18) to shed light on the diagnosis, prognosis, and treatment of this disease. These findings indicate that this malignancy is very rare along with poor prognosis. Surgery is the basic treatment often supplemented by radiotherapy or chemotherapy, and further study is needed to figure out long-term outcomes.