[A case of Wegener's granulomatosis associated with the syndrome of inappropriate secretion of ADH].

A 68 year-old woman was admitted with fever, productive cough and sore throat. A chest radiograph and a chest computed tomography showed multiple nodules in both lungs. Thoracoscopic lung biopsy was performed. The specimens showed vasculitis and geographic basophilic necrosis with palisading histiocytes, giant cells, and neutrophils. Wegener's granulomatosis was diagnosed. On the 5th hospital day, the serum sodium level was 128 mEq/l. Since secretion of antidiuretic hormone had continued despite a low plasma osmolarity, we diagnosed the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and initiated oral prednisolone and cyclophosphamide. As a result, the symptoms and image findings were improved, and serum sodium level became normal. This case was considered to be SIADH secondary to Wegener's granulomatosis.