%0 Case Reports %T A Rare Case of Methemoglobinemia after Ifosfamide Infusion in a 3-Year-Old Patient Treated for T-ALL. %A Suprunowicz M %A Marcinkiewicz K %A Leszczyńska E %A Krętowska-Grunwald A %A Płonowski M %A Tałałaj M %A Dakowicz Ł %A Krawczuk-Rybak M %A Sawicka-Żukowska M %J Int J Mol Sci %V 25 %N 7 %D 2024 Mar 28 %M 38612599 %F 6.208 %R 10.3390/ijms25073789 %X Methemoglobinemia is a potentially life-threatening, rare condition in which the oxygen-carrying capacity of hemoglobin is diminished. We present the case of a 3-year-old boy treated for T-cell acute lymphoblastic leukemia (T-ALL) who developed methemoglobinemia (MetHb 57.1%) as a side effect of ifosfamide administration. Due to his critical condition, the patient was transferred to the intensive care unit (ICU). The therapy included methylene blue administration, an exchange transfusion, catecholamine infusion, and steroids. Improving the general condition allowed for continuing chemotherapy without ifosfamide and completion of the HR2 block. Vigilance for methemoglobinemia as a very rare side effect should be widespread when using ifosfamide in the treatment protocols.