This report described two patients with small cell neuroendocrine carcinoma of the larynx (patient 1) and maxillary sinus (patient 2). Immunohistological examination was helpful for the diagnosis. Both patients had lymph node metastasis of the bilateral neck, but at the start of their treatment distant metastasis was not detected by conventional clinical examinations including systemic imaging examinations (computed tomography, magnetic resonance imaging, and radioisotope imaging). Patients responded to systemic chemotherapy with or without radiotherapy. Surgical treatment for the resultant primary tumor and lymph node metastasis was effective. However, after initial treatment, distant metastasis appeared in the brain (patient 1) and in the liver (patient 2). They died 16 months (patient 1) and 7 months (patient 2) after their initial diagnoses. Although chemoradiotherapy and surgical treatment was effective for the regional tumor, the treatment of distant metastasis was crucial for acquiring the long term survival.
