A study was made of the pathological findings of 14 cases of acute or subacute farmer's lung by transbronchial lung biopsy (TBLB). The conclusions were as follows:
1. Alveolitis were found in all patients. Two of the 14 patients had severe alveolitis, 7 moderate and 5 patients slight alveolitis.
2. Granuloma and Masson bodies were found in 4 patients, granuloma alone in 5 patients and Masson bodies in 2 patients.
3. Four patients were biopsied within one month after the onset of symptoms. All disclosed the findings of alveolitis and three of them had no graonuloma. All of them were also bipsied on 1.5 to 6 months after the onset of symptoms and showed granuloma and/or Masson bodies.
4. In 4 patients treated with steroids, severe alveolitis was not found, but granuloma and/or Masson bodies were observed. The pathological findings of 3 patients on the second biopsy after the steroid therapy showed improvement or some resolution.
