Syndrome of inappropriate antidiuretic hormone secretion in cancer of the head and neck.

The syndrome of inappropriate secretion of arginine vasopressin (AVP) known as the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by hyponatremia that results from water retention attributable to persistent AVP release. It may occur in a variety of malignant and nonmalignant lesions, with small cell or oat cell carcinoma of the lung by far responsible for the largest number of these cases. Cancer of the head and neck may be a rare cause of SIADH, and only a few such cases have been reported. We describe four patients with advanced cancer of the head and neck region with coexisting SIADH. Diagnosis and treatment are reported and the literature is reviewed. The possible occurrence of SIADH in the head and neck surgical practice should be kept in mind. Since SIADH is usually transient, water restriction and parenteral sodium chloride may be sufficient in overcoming the acute phase.