Please use this link to access this publication. Abstract Electronic cigarettes, pens, cartridges and other devices were developed as nicotine delivery systems not requiring combustion of tobacco leaves. This technology was subsequently employed to deliver the cannabis component tetrahydrocannabinol (THC) via products often manufactured without adequate quality oversight and sold illegally. Recently, five patients presenting within a 2-month period with acute respiratory failure due to acute lipoid pneumonia after inhaling THC-containing concentrates or oils have been described. We report a 28-year-old previously healthy man who presented in acute respiratory failure 2 weeks after initiating use of a street-purchased THC-containing vape cartridge. Bronchoalveolar lavage cytology with...