Immunohistochemical analysis of small cell carcinoma of the head and neck: a report of four patients and a review of sixteen patients in the literature with ectopic hormone production.

Small cell carcinoma (SCC) occurs mostly in the lung, and in some patients is accompanied by production of ectopic hormones. Small cell carcinoma of the head and neck is very rare. We report 4 patients with SCC of the head and neck (larynx, tonsil, maxillary sinus, and parotid gland). The patient with SCC of the maxillary sinus demonstrated a high level of plasma serotonin and overexpression of parathyroid hormone; however, he did not show any related symptoms. The patient with SCC of the tonsil showed the syndrome of inappropriate secretion of antidiuretic hormone associated with antidiuretic hormone hyperproduction at the terminal stage. In the literature, 16 patients with SCC of the head and neck with ectopic hormone production have been reported. Antidiuretic hormone and adrenocorticotropic hormone were the hormones that caused clinical symptoms (paraneoplastic syndromes). We believe that the evaluation of hormonal syndromes is valuable for diagnosis and treatment.