Methemoglobinemia Induced by Food During Chemotherapy in a Boy With Acute Lymphoblastic Leukemia and Literature Review.

Methemoglobinemia, a rare and potentially life-threatening condition in pediatric hematology-oncology patients, requires accurate cause identification for effective treatment. We report a case of a 7-year-old boy with acute lymphoblastic leukemia who developed methemoglobinemia during chemotherapy. Initial vitamin C treatment was ineffective, requiring methylene blue. A detailed dietary history revealed the consumption of nitrate-rich vegetables and rapeseed oil, suggesting these as potential triggers. Our literature review highlights the diverse etiologies of methemoglobinemia in this patient population, emphasizing the need for heightened clinical vigilance, and careful differentiation of possible causes to guide appropriate management.