A case of alveolar proteinosis associated with pulmonary nocardiosis

Two years ago, a 59-year-old man was admitted to his local hospital with fever and dyspnoea. A chest CT revealed multilobar consolidation, and Nocardia asteroides was cultured from tissue obtained by CT-guided transcutaneous lung biopsy. One year later, he was presented to our university hospital complaining of progressively worsening dyspnoea, fatigue, and general malaise. On examination, there was cyanosis and finger clubbing, and inspiratory crackles were heard over the lower two-thirds of both pulmonary fields. Serum lactate dehydrogenase (LDH) was markedly increased (993 U/l) and PaO2 on room air was 4.6 kPa (35 mm Hg) with a PCO2 of 5.2 kPa (40.2 mm Hg). A high-resolution chest CT scan showed intra-alveolar ground glass opacities associated with areas of airspace consolidation and interlobular thickening distributed in a bilateral geographic pattern. Bronchoscopy with bronchoalveolar lavage (BAL) yielded a milky fluid that contained extracellular, periodic acid-Schiff (PAS)-positive and Alcian blue-negative material, a typical feature of pulmonary alveolar proteinosis (PAP).