LAUSR

A 32-year old male presented with gradually progressive dry cough and breathlessness for 6 months. He denied hemoptysis, chest pain, orthopnea, and weight loss. He was recently diagnosed with mediastinal lymph node tuberculosis and was on antitubercular therapy. He denied smoking or alcohol use. His blood pressure was 140/80 mmHg, heart rate 140 beats/min, respiratory rate 28/min, temperature 37.2 °C, and oxygen saturation 85% on room air. Lung examination showed bilateral basal fine crepitations. White blood cell count was 11,700 per mm3. Renal and liver function tests were normal. Pro-calcitonin, D-dimer, pro-brain natriuretic peptide and respiratory viral testing was within normal limits or negative. Chest radiograph showed bilateral hazy opacities involving both upper and lower lung zones (Fig. 1a). Computed tomography (CT) of chest showed bilateral ground-glass opacities (GGO) with interlobular thickening suggestive of a crazy paving appearance, and mediastinal lymphadenopathy (Fig. 1b). Bronchoscopy showed a normal endobronchial tree without any lesions. Broncho-alveolar lavage returned an opaque milky-white fluid due to the abundant lipoproteinaceous material (Fig. 1c). Gram stain, culture, silver stain and acid-fast bacilli stain was negative. Cytology revealed large acellular eosinophilic aggregates, macrophages filled with periodic acid schiff (PAS) positive proteinaceous material, sparse lymphocytes with no malignant cells. Trans-bronchial lung biopsy revealed eosinophilic PAS positive material. He was diagnosed with pulmonary alveolar proteinosis (PAP). He was intubated with a double lumen tube and whole lung lavage (WLL) was initiated. Due to persistent hypoxemia, segmental right lung lavage was preferred. Follow-up chest radiograph revealed new right sided pneumothorax (Fig. 1d). Chest tube was placed. Patient recovered well afterwards. This was followed by left lung segmental lavage. After lavage of both lungs, the patient improved significantly and so did the chest radiograph (Fig. 1e). PAP is characterized by accumulation of PAS positive lipoproteinacious material in the alveoli and terminal bronchioles which decreases in turbidity as serial lavages are performed [1]. The etiology is commonly primary autoimmune and secondary form (due to dust inhalation) is unusual [2]. It is rarely seen in pneumocystis jirovecci or mycobacterial infection. Proposed pathogenesis include reduced function of granulocyte–macrophage colony-stimulating factor (GMCSF) and macrophage dysfunction resulting in inadequate handling of surfactant and accumulation PAS positive material in the alveolar space [1]. High resolution CT (HRCT) shows ‘crazy paving’ suggested by GGO with thickened septa [3]. Differential Diagnosis for ‘crazy paving’ pattern are organizing pneumonia, acute interstitial pneumonia, pneumocystis jirovecci pneumonia and acute respiratory distress syndrome. Confirmatory diagnosis requires bronchoscopy with lavage and biopsy. Milky-white fluid positive for PAS in conjunction with GGO on HRCT is highly supportive of PAP [1]. Most patients present with respiratory symptoms such as dry cough and shortness of breath. Hypoxemia is common in advanced disease. Patients with mild disease recover with supportive treatment while those with severe disease require WLL [1]. WLL is performed in one lung at a time via double-lumen endotracheal tube. Patients are placed in * Namrata Singhania [email protected]