[A case of pulmonary tuberculosis initially presented with syndrome of inappropriate secretion of antidiuretic hormone (SIADH)].

A 90-year old man was admitted to a hospital because of consciousness loss with hyponatremia. Although his symptom promptly improved with Na supply, his chest X-ray film showed pulmonary infiltration and direct microscopy of sputum smear was positive for acid-fast bacilli, then he was referred our hospital and was admitted. We made a clinical diagnosis of pulmonary tuberculosis with SIADH based on detailed examinations. But he should neither respiratory symptoms nor fever. He was medicated with the standard antituberculosis drugs with fluid restriction, and his tuberculosis and hyponatremia were improved gradually. We should be more careful about pulmonary tuberculosis irrespective of its severity as a cause of SIADH.