“Breathtaking Protein”: An Interesting Case of Acquired Pulmonary Alveolar Proteinosis With Emphysematous Changes and Pneumothorax

SESSION TITLE: Diffuse Lung Disease SESSION TYPE: Case Report Poster PRESENTED ON: Sunday, April 17, 2016 at 11:45 AM - 12:45 PM INTRODUCTION: Pulmonary Alveolar Proteinosis (PAP) is an idiopathic lung disease characterized by abnormal alveolar surfactant accumulation and hypoxemic respiratory insufficiency. The rarity of the condition, variable clinical course and limited treatment options can make it a therapeutic challenge. 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. DISCUSSION: PAP can be hereditary, secondary or autoimmune. The autoimmune form is the most common due to acquired GM-CSF (Granulocyte-Macrophage Colony Stimulating Factor) antibodies. Upto 70% of patients are smokers and a 2:1 male predominance is seen. PAP is diagnosed with a combination of HRCT and BAL in upto 60% of the cases. TBBX or open lung biopsy are warranted in inconclusive cases and to rule out secondary causes. Upto 50% patients are asymptomatic. Contrary to the name, CT changes are not entirely alveolar in PAP with apical emphysematous changes seen in upto 7% patients likely secondary to tension cysts developing due to alveolar distension from lipoproteinaceous material with smoking related oxidative stress as a contributing factor.“Crazy paving” due to thickened intralobular structures and interlobular septa on HRCT is characteristic but not pathognomonic. Only 2 confirmed cases of pneumothoraces secondary to PAP have been documented in the literature to date albeit posthumously. Currently, WLL is the only accepted treatment with upto 40% of patients showing remission after one session. Subcutaneous and Inhaled GM-CSF are still inferior to WLL. Plasmapheresis and Rituximab use for PAP warrant further research. CONCLUSIONS: PAP is rare diffuse lung disease with varied clinical and radiological presentations. Emphysematous changes and Pneumothoraces due to PAP are extremely rare but possible and can be the presenting symptom as in this patient. Reference #1: Mariana, D. (2012). Pulmonary alveolar lipoproteinosis asociated with emphysematous areas. Rom J Morphol Embryol 53,173-177 Reference #2: Anton, H. C. (1967). Pulmonary Alveolar Proteinosis presenting with pneumothorax. Clinical Radiology 18, 428-431 DISCLOSURE: The following authors have nothing to disclose: Kavitha Bagavathy, Renli Qiao, RajKumar Dasgupta No Product/Research Disclosure Information