A

Early dyspnea, fever, and bilateral infiltrates within days of starting ATRA for acute promyelocytic leukemia signal differentiation (ATRA) syndrome, whose first-line therapy is prompt high-dose intravenous dexamethasone to abort the inflammatory capillary-leak process [Montesinos, 2011, PMID 22220256; Sanz, 2014, PMID 24627526; Rego, 2011, PMID 22110898].