The curious incident of the cast in the airway.

A 52-year-old man presented with progressive dyspnoea and productive cough over 4 months. He was in type 2 respiratory failure (pO2 7.99 kPa/60 mm Hg; pCO2 9.32 kPa/70 mm Hg) with fluid overload and was started on non-invasive ventilation and intravenous diuresis in intensive care. Physical examination was significant for his short neck, small jaw and body mass index of 50. He was expectorating thick branching sputum, and bronchial casts were retrieved on bronchoscopy (figure 1A). Figure 1 (A) Image of bronchial cast removed during bronchoscopy. (B) Section of laminated proteinaceous cast material (black arrow) with admixed small lymphocytes and foamy macrophages (black arrow) with scale bar (H&E ×40). A chest CT showed endobronchial material and extensive bilateral ground glass opacification (figure 2A,B). Sputum cultures were negative but biochemical analysis revealed high triglycerides. Histopathological analysis revealed a fibrinous sample with foamy macrophages, occasional eosinophils and mildly atypical epithelioid cells (figure …