Acute Myeloid Leukaemia

This blood film represents a haematological emergency. The appearance is clearly one of leukaemia - the white cell count is in the hundreds and the platelet count is very low. The white blood cells have a monomorphic, immature appearance with open chromatin, a prominent nucleolus and a high NC ratio. These are all blasts.

The reson this is more significant than a leukaemia with a lower white count is that the severity of the leukocytosis combined with the clumping make it much more likely the patient is suffering from a complication known as leukostasis. As if having leukaemia is not bad enough, this is a complication where the clumps of blasts occlude blood vessels and cause multi-organ damage ranging from visual loss to renal impairment. Without treatment, it is universally fatal. A blood film like this needs immediate escalation!

It is difficult on this film to determine the origin of the leukaemia. The blasts are quite uniform, normally a feature of lymphoid leukaemias however there is some heterogeneity in the nuclear contour, and even more suggestive of a myeloid lineage is that some of the blasts appear to be granular. I couldn't find any auer rods in the film.

There are occasional neutrophils, but those seen are hypogranular also suggesting a myeloid lineage for the pathology. Overall though, if you commented that this was leukaemia then that is a  good start - narrowing it down to myeloid is excellent. Of course, flow cytometry, bone marrow examination (and probably leukapheresis in this case) are the next steps.