Objectives: Small cell carcinomas in extrapulmonary sites (ESmCCs) are very rare. ESmCCs originating in the head and neck account for approximately 10% of all ESmCCs, and there are few reports about this disease. ESmCCs have an aggressive natural history characterized by widespread metastasis. The aim of this study was to investigate the characteristics and outcomes of patients with ESmCCs of the head and neck.
Methods: The outcomes of 21 patients with ESmCCs of the head and neck treated between January 2001 and December 2015 at the authors' hospital and associated facilities were reviewed.
Results: There were 18 men and 3 women, and the median age was 74 years (range, 53-91 years). The tumor site was the larynx in 6 patients; the paranasal sinus in 5; the hypopharynx in 3; the oropharynx in 2; the nasopharynx in 2; and the oral cavity, salivary gland, and primary unknown in 1 patient each. The extent of the disease was staged as follows: stage I or II, 3 cases; stage III, 4 cases; stage IVA, 9 cases; stage IVB, 1 case; and stage IVC, 4 cases. The median observation time was 17 months (range, 1-103 months). Four patients (19%) had distant metastasis at initial treatment, and 13 patients (62%) developed distant metastasis within 3 years. Treatments were administered, including radical surgery (9 patients), radiation therapy (5 patients), chemoradiotherapy (7 patients), and chemotherapy (6 patients). The 1- and 3-year overall survival rates of patients were 56% and 37%, respectively. More than half of the patients died of distant metastasis.
Conclusions: ESmCCs of the head and neck have a poor prognosis, similar to those of carcinomas in many other sites. Control of distant metastasis would contribute to improving the prognosis of ESmCCs of the head and neck. Further studies are required for better understanding these disease entities and their response to treatment modalities.
Keywords: extrapulmonary small cell carcinoma; head and neck carcinoma; neuroendocrine carcinoma; small cell carcinoma.