Some types of acute leukemia are composed of only blasts (no differentiating neutrophils, no monocytic precursors, just a sea of blasts). In those cases, look for Auer rods. A blast with an Auer rod can only be a myeloblast! It cannot be a lymphoblast, or a monoblast, or any other kind of blast. So if you see blasts with Auer rods, you know it is some type of acute myeloid leukemia. Remember, though, that the converse is not true: just because you don’t see Auer rods, that does not mean that the blast is not a myeloblast. Some myeloblasts have Auer rods, and some don’t. So if you see Auer rods, it is an AML. If you don’t, it still could be an AML.
Thanks for reminding me about Auer Rods!
look a Seal screaming! poor thing. AML is bad indeed
I’ll never forget about Auer Rods thank you!
in which type of AML we found most aur rod body?
What if we find auer rods in blasts whose percentage in bone marrow aspirate is less than the percentage required for diagnosing AML (<20%)? Is the diagnosis would still be AML or Auer rods can be found in normal blasts?
Good question! Auer rods are never seen in normal blasts. If the number of blasts is not high enough to call a case AML (20%), then the case would most likely fall into the category of myelodysplasia (MDS).
AML-M1 and M2 have the most Auer rods of all the types of AML. You do see lots of Auer rods in AML-M3 – but they tend to congregate in a single blast (this type of cell – a blast with many, many Auer rods – is called a faggot cell).