Pulmonary Alveolar Proteinosis an under Diagnosed Entity

Pulmonary alveolar proteinosis (PAP) is a rare, congenital or acquired disease characterised by impaired surfactant clearance that leads to accumulation of an amorphous, lipoproteinaceous material in the alveoli, largely made up of surfactant protein (SP) - A,B,C,D which are Periodic Acid Schiff (PAS) positive. A 53 year old male presented with anorexia, weight loss, progressive dyspnoea on exertion&cough with whitish mucoid expectoration. Investigations showed severe hypoxia and elevated serum LDH. X ray chest had Bat-wing appearance with bilateral infiltration with spared lung apices. HRCT chest showed bilateral alveolar filling with 'crazy-pavement' appearance with well preserved interlobular and alveolar architecture suggestive of PAP. Bronchoscopic aspiration of bronchoalveolar lavage (BAL) fluid examination confirmed the diagnosis of PAP. Patient improved with alveolar aspiration.