Severe Methotrexate Toxicity Following a Capizzi Cycle in an Obese Adolescent With Acute Lymphoblastic Leukemia and Hepatic Steatosis.

Methotrexate is a major component of pediatric leukemia treatment. While toxicities are common after high-dose methotrexate, escalating dose methotrexate (Capizzi methotrexate) is typically well-tolerated. We report an adolescent Hispanic female with pre-B acute lymphoblastic leukemia, preexisting obesity and hepatic steatosis who developed severe multiorgan failure following an escalating dose of methotrexate with delayed methotrexate excretion of 11 days.