A 72-year-old man was admitted to the haematology-oncology service from the medical intensive care unit of a tertiary care centre in the USA for altered mental status and persistent hypoxia. The patient had initially presented at a subacute rehabilitation facility for acute respiratory failure in the setting of a known pulmonary embolism and new aspiration pneumonia. Notably, the patient had a history of T1bN0M0 non-small-cell lung carcinoma, treated with radiotherapy 8 months before presentation, and a history of prostate cancer (Gleason score of 6) on active surveillance, with a increasing prostate-specific antigen level.