Auerse rods are red- to pink-colored, rod-shaped cytoplasmic inclusions that occur exclusively in cells of the myeloid lineage. They arise from aggregation of lysosomal proteins, mainly myeloperoxidase and acid phosphatase.

Unlike finding Auerse Rods in Blasts, their presence in neutrophils is a rare finding. They have been described in neutrophils in several forms of acute myeloid leukemia (AML), including AML with t(8;21)-translocation, acute promyelocyte leukemia (APL), AML with maturation and mixed lineage leukemia. They may also occur in APL after treatment with all-trans-retinoic acid (ATRA).