A diagnostic dilemma: autoimmune pulmonary alveolar Proteinosis unmasked by vaping-induced lung injury.

A 65-year-old smoker with recent vaping resumption, found to have elevated anti-GM-CSF antibodies suggestive of autoimmune pulmonary alveolar proteinosis (PAP). However, bronchoalveolar lavage and whole lung lavage were inconclusive, raising suspicion for concurrent E-cigarettes or vaping-associated lung injury (EVALI). The patient showed no clinical response to corticosteroids and eventually passed away. Post-mortem pathology confirmed surfactant accumulation and foamy macrophages but also showed features of diffuse alveolar damage. This case underscores the diagnostic and management challenges when PAP and inhalational lung injuries overlap.