Auer rods (orAuer bodies) are large,crystallinecytoplasmicinclusion bodies sometimes observed inmyeloidblast cells duringacute myeloid leukemia,acute promyelocytic leukemia,high-grademyelodysplastic syndromes andmyeloproliferative disorders. Composed of fusedlysosomes and rich inlysosomal enzymes, Auer rods areazurophilic and can resemble needles, commas, diamonds, rectangles, corkscrews, or (rarely) granules.[1]
Although Auer rods are named for American physiologistJohn Auer,[2] they were first described in 1905 by Canadian physicianThomas McCrae, then atJohns Hopkins Hospital,[3] as Auer himself acknowledged in his 1906 paper. Both McCrae and Auer mistakenly thought that the cells containing the rods werelymphoblasts.[4]
