[A case of necrotizing sarcoid granulomatosis diagnosed by open lung biopsy].

A 32-year-old female complained of productive cough and bloody sputum. Infiltrative shadows and cavitary lesions with thick and irregular wall in the bilateral lung fields and the swelling of mediastinal lymph nodes were pointed out on the chest radiography. Physical examination revealed no abnormal findings. ESR and the level of the serum angiotensin converting enzyme were slightly elevated. In the BAL (broncho-alveolar lavage) fluid, lymphocytes and neutrophils increased, and the OKT4/OKT8 ratio of the lymphocytes was 0.81. Open lung biopsy revealed numerous sarcoid granulomas with granulomatous vasculitis in the cavity wall, surrounding infiltrative lesions and hilar lymph nodes. After the administration of prednisolone, the infiltrative shadows and the cavitary lesions showed marked improvement. It was concluded that open lung biopsy is necessary for the diagnosis of NSG because the differential diagnosis between NSG and limited form of Wegener's granulomatosis is extremely difficult from such a small lung specimen as that obtained by trans-bronchial lung biopsy.