Auer rod

Crystalline cytoplasmic inclusion bodies

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]

Eponym

Although Auer rods are named for American physiologist John Auer,^[2] they were first described in 1905 by Canadian physician Thomas McCrae, then at Johns Hopkins Hospital,^[3] as Auer himself acknowledged in his 1906 paper. Both McCrae and Auer mistakenly thought that the cells containing the rods were lymphoblasts.^[4]

Additional images

Bone marrow aspirate showing acute myeloid leukemia with Auer rods in several blasts

References

^ 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.
^ Auer, John (1906). "Some hitherto undescribed structures found in the large lymphocytes of a case of acute leukaemia". American Journal of the Medical Sciences. 131 (6): 1002–1015. doi:10.1097/00000441-190606000-00008. ISSN 0002-9629. S2CID 71853154.
^ McCrae, Thomas (February 1905). "Acute lymphatic leukaemia with a report of five cases". British Medical Journal. 1 (2304): 404–408. doi:10.1136/bmj.1.2304.404. PMC 2319598. PMID 20761949.
^ Bain, Barbara (August 2011). "Auer rods or McCrae rods?". American Journal of Hematology. 86 (8): 689. doi:10.1002/ajh.21978. PMID 21761434.

External links

Image at NIH/MedlinePlus
Slides at wadsworth.org
Image at University of Utah

Blood film findings

Red blood cells

Size	Anisocytosis Macrocytosis Microcytosis
Shape	Poikilocytosis Membrane abnormalities Acanthocyte Codocyte Elliptocyte Hereditary elliptocytosis Spherocyte Hereditary spherocytosis Dacrocyte Echinocyte Schistocyte Degmacyte Sickle cell/drepanocyte Sickle cell disease Stomatocyte Hereditary stomatocytosis
Colour	Anisochromia Hypochromic anemia Polychromasia
Inclusion bodies	Developmental Howell–Jolly body Basophilic stippling Pappenheimer bodies Cabot rings Hemoglobin precipitation Heinz body
Other	Haemoconia Red cell agglutination Rouleaux

White blood cells

Lymphocytes	Reactive lymphocyte Smudge cell Russell bodies
Granulocytes	Hypersegmented neutrophil Arneth count Pelger–Huët anomaly Döhle bodies Toxic granulation Toxic vacuolation Critical green inclusion Alder–Reilly anomaly Jordans' anomaly Left shift
Other	Auer rod