SESSION TITLE: Miscellaneous Cases III
SESSION TYPE: Affiliate Case Report Slide
PRESENTED ON: Sunday, October 27, 2013 at 03:00 PM - 04:00 PM
INTRODUCTION: Pulmonary Alveolar Proteinosis (PAP) is a rare diffuse lung disease characterized by accumulation of Periodic acid-Schiff (PAS) positive lipoproteinaceous material in distal airspaces, with preservation of underlying lung architecture. Primary PAP is an autoimmune disorder associated with anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies. Secondary PAP, without detectable anti-GM-CSF antibodies, has been associated with lung carcinoma. We describe the first reported case of PAP associated with lung carcinoma and positive anti-GM-CSF antibodies.
CASE PRESENTATION: A 64-year-old male smoker with progressive dyspnea, productive cough and unintentional weight loss presented for evaluation. Physical examination revealed diffuse inspiratory crackles and resting hypoxemia. CXR demonstrated extensive bilateral reticular nodular infiltrates and an ill-defined right apical lung opacity. Chest CT and PET scan demonstrated bilateral diffuse ground glass opacities with thickened interlobular septa in a “crazy paving” pattern and an FDG avid right apical lung mass with associated paratracheal lymph nodes. Transbronchial biopsies revealed PAS positive intra-alveolar granular material consistent with PAP. Whole lung lavage returned copious cloudy proteinaceous material. Anti-GM-CSF antibodies were positive at 105.1 mcg/mL. Infectious work-up was notable for disseminated MAI, which was treated. CT guided biopsy of the lung mass revealed primary lung adenocarcinoma. Staging mediastinoscopy documented IIIA disease. He was referred for neo-adjuvant chemotherapy.
DISCUSSION: Primary PAP is associated with anti-GM-CSF antibodies. Low GM-CSF levels are thought to disrupt alveolar macrophage function and impair surfactant processing, leading to progressive respiratory failure. Secondary PAP is less common and associated with hematologic malignancies, opportunistic infections, immunodeficiency syndromes, bone marrow transplantation, pneumoconiosis and rarely solid organ malignancies. Treatment of PAP typically includes whole lung lavage; supplemental GM-CSF, rituximab, plasmapheresis, and lung transplantation are additional treatment options.
CONCLUSIONS: To date there are only 7 published case reports of secondary PAP associated with a solid organ malignancy. Anti-GM-CSF antibodies are very sensitive and specific for primary PAP but have not been described as a feature of secondary PAP. To our knowledge this is the first reported case of PAP presenting with lung carcinoma demonstrating the presence of anti-GM-CSF antibodies. It is unclear if this reflects an exceptionally unlikely coincidence or a causal relationship.
Reference #1: Trapnell BC, et al. Pulmonary alveolar proteinosis. NEJM. 2003;349:2527-39.
Reference #2: Su K, et al. Lung cancer may develop subsequently or coincidently with pulmonary alveolar proteinosis. Lung Cancer. 2007;58:144-148.
Reference #3: Kadota J, et al. Pulmonary alveolar proteinosis with lung squamous cell carcinoma. Respir Med. 1999;93(2):138-40.
DISCLOSURE: The following authors have nothing to disclose: David Kamrava, Dale Jun, Svetlana Kotova, Tisha Wang, Scott Oh, Jaime Betancourt
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