Thanks for all of your responses. The full blood count of our patient showed Hb 82g/L, PLT 34×10*9/L, WCC 6.2×10*9/L, neuts 0.34×10*9/L. The film showed abnormal leukaemic blast cells which are occasionally bilobed and heavily granulated with stacks of Auer rods (so called faggot cells). This is acute promyelocytic leukaemia, a varient of acute myeloid leukaemia (M3 in old terminology). It is usually associated with the t(15;17) in the leukaemic clone causing the PML:RARA fusion gene. It is a medical emergency as death can occur due to coagulopathy if not promptly treated. However the long term cure rate is excellent. It is important to check the coagulation results and aggressively replace clotting factors with FFP and cryoprecipitate as well as platelet transfusion. All trans retinotic acid (ATRA), a vitamin A derivative, can cause differentiation of the abnormal promyelocytes and must be started as soon as the diagnosis is contemplated before confirmatory cytogenetic tests.