[Acute Promyelocytic Leukemia - A Rare, Life-Threatening Disease with High Healing Chance]

The acute promyelocytic leukemia (APL) is a rare disease. However, if diagnosed early and treated immediately high cure rates can be achieved. Signs of hematopoietic insufficiency such as cytopenias or leucocytosis can be present at first presentation of the patients. Moreover, hemorrhagic diatheses due to coagulpathy are present in approximately 80 % of cases and contribute substatially to the high early death rate in APL patients, which has been reported as high as 30 % in population based studies. In case of initial suspicion of APL treatment with all-trans retinoic acid (ATRA) should be initated immediately to reduce the risk of fatal bleeding events and confirmation or exclusion of the PML-RARA transcript should not be awaited before start of ATRA treatment. While patients with a low or intermediate risk of relapse are treated with a combination of ATRA and arsenic trioxide (ATO), those with high risk of relapse still receive a combination regimen consisting of ATRA, anthracyclines and cytosine-arabinosid. However, treatment strategies are under clinical investigation aiming at reducing the administration of conventional chemotherapy in high risk APL patients. With the current treatment approaches cure rates of approximately 90 % of the patients with low or intermeditae risk APL can be achieved. Nevertheless, particularly the high initial death rate warrants further clinical and pathiobiologic studies to identify targets and means to decrease hemorrhagic complications in patients with APL.