A 71-year-old male complaining of chest pain was admitted to our hospital. A single cavitary mass shadow was observed on chest X-ray films. Urinalysis revealed microscopic hematuria. CT examination demonstrated a tumorous shadow in the maxillary sinus. The diagnosis of Wegener's granulomatosis was histologically established by biopsy specimens from the nasal mucosa which showed necrotizing vasculitis and granuloma with fibrinoid degeneration. He was treated with combination therapy of prednisolone and cyclophosphamide. The abnormal shadows on chest X-ray and in the maxillary sinus on CT improved rapidly, but the patient developed progressive weight loss and complained of cold intolerance, weakness and dysphagia. Serum T3, T4 and TSH were found to be reduced. Anterior pituitary function tests showed reduction of TSH, GH and ACTH responses, which was probably due to irreversible vasculitis.