Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) induced by squamous cell carcinoma of larynx: A case report

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most frequent paraneoplastic syndrome associated with hyponatremia in patients with tumours. The most common malignancy associated with SIADH is small cell tumour of lung. 1 Association of SIADH with head and neck malignancies is only seen in 1.5% of cases. We are reporting a case of 70 year old male, who came to emergency with irritable behaviour and stridor. On indirect laryngoscopy, there was proliferating mass right vocal cord. Emergency tracheostomy was done. Even though the blood pressure and pulse were within normal limits, patient was irritable and semiconscious. His serum sodium level was 110 mg/dl. Patient was started on fluid restriction and 3% saline infusion. On biopsy of mass right vocal cod, it was squamous cell carcinoma.