Hyperleucocytosis and Leucostasis in Acute Myeloid Leukaemia: A Challenging Clinical Situation

Hyperleucocytosis is defined as a white cell count (WBC) >50 x 109/L or commonly 100 x 109/L in a patient with leukaemia. Hyperleucocytosis with leucostasis is most often seen in patients with Acute Myeloid leukaemia (AML). AML with hyperleucocytosis is thought to have a poor prognosis because of a higher risk of early death due to complications such as disseminated intravascular coagulation (DIC), tumour lysis syndrome (TLS), and leucostasis, as well as a higher likelihood of long-term relapse. Leucostasis is considered a medical emergency since it has the potential to cause ischemia in vital organs with high mortality requiring immediate intervention. The molecular mechanisms that cause hyperleucocytosis are not well known. The molecular mechanisms behind hyperleucocytosis remain poorly understood.