Auer rod

Myeloblast with an Auer rod (to the left of the nucleus).

Auer rods (or Auer bodies) are large, crystalline cytoplasmic inclusion bodies sometimes observed in myeloid blast cells during acute myeloid leukemia, acute promyelocytic leukemia, high-grade myelodysplastic syndromes and myeloproliferative disorders. Composed of fused lysosomes and rich in lysosomal enzymes, Auer rods are azurophilic and can resemble needles, commas, diamonds, rectangles, corkscrews, or (rarely) granules.[1]

  1. ^ Ackerman, G. Adolph (1950). "Microscopic and Histochemical Studies on the Auer Bodies in Leukemic Cells". Blood. 5 (9): 847–863. doi:10.1182/blood.V5.9.847.847. PMID 15434012.