In late November 2023, a 21-year-old man with the diagnosis of Pre-B-cell ALL admitted to the hematology department of Omid hospital affiliated to Isfahan \RL University of Medical Sciences (Isfahan, Iran) for receiving induction chemotherapy. The chemotherapy regimen was CALGB 10403. The prophylactic regimen during chemotherapy were levofloxacin, co-trimuxazole, acyclovir and fluconazole. 5 days after the end of the course of induction chemotherapy the patient became febrile (T: 38.5).

He presented fatigue, \RL occasional dry cough, and left pleuritic chest pain with normal vital signs and physical examination. Oxygen saturation was 96% while the patient was breathing ambient air.