Introduction:
Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening condition characterised by obstruction of the small veins of the liver. Although typically associated with haematopoietic stem cell transplantation, VOD/SOS may also occur following intensive multimodal chemotherapy regimens. In children, symptoms of VOD/SOS are refractory thrombocytopaenia, weight gain, hepatomegaly, ascites and fluid retention, hyperbilirubinaemia and sometimes right upper quadrant pain.

Methods:
Here, we present a case series of six paediatric patients with acute lymphoblastic leukaemia who developed severe VOD/SOS while receiving standard AIEOP-BFM ALL protocol treatment.

Results/Conclusions:
All patients responded promptly to defibrotide treatment and exhibited favourable clinical outcomes.

Trial Registration:
The authors have confirmed clinical trial registration is not needed for this submission.