Neuroendocrine Carcinoma of the Submandibular Gland in an Older Adult: A Rare Case and Literature Review

Background:This report describes the case of a 78-year-old man with neuroendocrine carcinoma of the submandibular gland.This is an exceptionally rare and aggressive malignancy, with only a limited number of cases reported in the literature.Due to its low incidence and histopathologic overlap with other tumors, its diagnosis and management remain challenging. Case Report:We report the case of a 78-year-old White man with no history of smoking or alcohol use and with no relevant comorbidities, who presented with a painless, rapidly enlarging left submandibular mass measuring approximately 64.5 cm.Contrast-enhanced CT revealed a large tumor with central necrosis extending into the subcutaneous plane.The patient underwent en bloc surgical resection of the tumor with associated cervical lymph nodes.Histopathological examination demonstrated a high-grade neuroendocrine carcinoma, characterized by large nests and trabeculae of tumor cells with a high nucleus-to-cytoplasm ratio, nuclear hyperchromasia, high mitotic activity, and areas of necrosis.Immunohistochemistry showed positivity for chromogranin A, cytokeratin AE1/AE3, and CD56, supporting the diagnosis of neuroendocrine carcinoma.Postoperative management included adjuvant medical therapy, and long-term radiological follow-up demonstrated no evidence of recurrence at 4 years.In addition, a systematic review of the literature was performed, identifying 27 welldocumented cases of submandibular gland neuroendocrine carcinoma. Conclusions:Submandibular gland neuroendocrine carcinoma is a rare and highly aggressive neoplasm requiring a multidisciplinary diagnostic and therapeutic approach.Given the lack of standardized treatment protocols, further research, molecular profiling, and multicentric studies are needed to develop personalized therapeutic strategies and improve patient outcomes.