In 2005-2010, six patients (3.9%) out of total 154 children treated for acute lymphoblastic leukaemia developed symptomatic venous thrombosis. Venous thrombosis occurred in 4 cases during induction, once during re-induction and once after the 4th block of chemotherapy for ALL relapse.
Out of the 38 patients who received preventive anticoagulant treatment, 2 (5.3%) developed venous thrombosis. In all cases of venous thrombosis, a combination of risk factors such as central venous line, corticosteroids and L-asparaginase was present.
Inherited thrombogenic risk factors did not appear to represent relevant risk factors for venous thrombosis in this group of children with acute lymphoblastic leukaemia treated at our centre. Our data correspond to those relating to deep venous thrombosis cited in literature and their incidence is typical for the induction phase of ALL treatment.