Primary poorly differentiated small cell type neuroendocrine carcinoma of the hypopharynx.

The incidence of primary poorly differentiated neuroendocrine carcinoma (PDNC) of the hypopharynx iŝ4%. However, the disease pathogenesis, natural history, and prognostic factors remain poorly understood. We report the case of a 66-year-old man who presented with multiple metastases from primary PDNC of the hypopharynx. Physical examination revealed ã3×4 cm left cervical mass located at the level III, with tenderness and an unclear boundary. Laryngoscopy revealed a large mass arising from the posterior hypopharynx; glottis and vocal cord movements were invisible. After consultation with our head and neck oncological multidisciplinary team, diagnosis and specific treatment plan were made. Under general anesthesia, a biopsy sample was obtained via suspension laryngoscopy. Routine pathology revealed small cell carcinoma. Immunohistochemical staining identified neoplastic cells that were positive for cytokeratins, CD56, chromogranin A, and synaptophysin. The Ki-67 mitotic index approached 80%. These findings confirmed hypopharyngeal PDNC, and chemotherapy was prescribed. After 7 months, the tumor metastasized to the left side of the anterior chest wall, bilateral lungs, left liver, and skeleton. The soft tissue of the chest wall was biopsied, and pathology revealed PDNC. Subsequent examinations over the next 4 months confirmed multiple liver metastatic lesions. The patient succumbed to the cancer progression a month later. Here, we systematically review the clinical manifestations, pathogenesis, prognostic factors, and treatment of the disease. In conclusion, patients always have a poor prognosis due to a lack of optimal treatment.