Hemophagocytic lymphohistiocytosis (HLH) is a multi-system inflammatory condition that has been observed as a rare adverse effect of the COVID19 vaccination. AML occurring in a pediatric patient as HLH enters remission has never been documented previously. Our case describes a 17-year-old male who was treated for this pathology with immunosuppressants and two different chemotherapeutic protocols. Due to the aggressive nature of his MLL-rearranged genetic profile, this cancer was pervasive and refractory to treatment.