Background: Vinblastine (VBL) is a cytostatic drug frequently applied in children with
lymphoma and progressive low-grade glioma (LGG), with hematotoxicity as the main side effect.
Case Report: Here, the case of a 7-month-old girl with tumor progression of an LGG during standard
chemotherapy with carboplatin and vincristine, is presented. Switching to VBL led to a 20-30-
fold increase of transaminases (grade IV CTCAE 5.0), spontaneously resolving after the end of
treatment. The toxicity is possibly age-related since it did not re-occur at the restart of VBL at 4
years old. This finding might have consequences for toxicity screening in future protocols, especially
when including infants.