CASE PRESENTATION: A 43 year old man with a 30 pack year smoking history was referred to our hospital for management of his “lung disease”. He initially presented with a large right spontaneous pneumothorax requiring a chest tube. He had a similar pneumothorax 6 months prior. He has had a non productive cough and required supplemental oxygen ever since. On presentation, his respiratory rate was 26 breaths/min with oxygen saturation of 94% on 3L nasal cannula and had diminished breath sounds with coarse bibasilar crackles. HRCT chest showed apical bullous disease with bilateral septal thickening and confluent ground glass attenuation. On Bronchoscopy, copious white mucoid material was seen throughout the airways. Broncho alveolar lavage (BAL) and Transbronchial biopsy (TBBX) revealed Periodic Acid Schiff (PAS) positive, intra alveolar eosinophilic material, confirming a diagnosis of PAP. Infectious and malignancy work up were negative. He subsequently underwent whole lung lavage (WLL) of his left lung with good response.