ICSH recommendations for the standardization of nomenclature and grading of peripheral blood cell morphological features

L. Palmer et al. 2015

RED BLOOD CELLS

Red cell Agglutination

Recommendation: report the presence of agglutination when observed.

Rouleaux formation

Recommendation: Report the presence of rouleaux when observed.

Anisocytosis

Increased variability in RBC size

Recommendation:

Report the RDW as a measure of the degree of variation in red cell size

Dimorphism

Presence of two distinct RBC populations

Recommendation:

Report the presence of dimorphism and describe the two populations

Hypochromia

Recommendation:

MCH should be used to gauge hypochromia

Reduction in RBC staining with an increase in central pallor to greater than one-third of the RBC diameter.

Macrocytes

Recommendation:

MCV should be used to gauge red cell size (degree of macrocytosis)

Enlarged red cells with a diameter greater than 8.5 mm (MCV > 100 fL)

Oval macrocyte

Recommendation:

Perform microscopic grading of oval macrocyte. Few/1+ N/A Mod/2+ 2-5% Many/3+ >5%

Microcytes

Recommendation:

MCV should be used to gauge red cell size (degree of microcytosis)

small red blood cells with a diameter of less than 7 mm (MCV < 80 fL)

Polychromasia

Recommendation:

Perform microscopic grading of polychromasia. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Immature red cells that are pinkish blue-grey in appearance due to residual ribosomal RNA.

Acanthocytes

Recommendation:

Perform microscopic grading of acanthocytes. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Synonym: astrocyte, burr cell, prickle cell, spur cell, thorn cell

Bite cell

Recommendation:

Perform microscopic grading of bite cells. Few/1+ N/A Mod/2+ 1-2% Many/3+ >2%

Keratocyte

Blister cells

Recommendation:

Perform microscopic grading of blister cells. Few/1+ N/A Mod/2+ 1-2% Many/3+ >2%

Synonym: puddle cell, eccentrocyte

Echinocytes

Recommendation:

Perform microscopic grading of echinocyte cells. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Synonym: crenated cell, poikilocyte, spur cell, spiculated cell, sputnik cell, star cell, berry cell, mulberry cell,

Elliptocytes/Ovalocytes

Recommendation:

Perform microscopic grading of elliptocytes and ovalocytes. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Synonym: bacillary cell, cigar cell, pencil cell.

Elliptocyte: The long axis is more than twice the short axis

Ovalocyte: The long axis is less than twice the short axis

Irregulary contracted cells

Recommendation:

Perform microscopic grading of these cells. Few/1+ N/A Mod/2+ 1-2% Many/3+ >2%

Poikilocytes

Recommendation:

Report the abnormal specific cell shape rather than use poikilocytosis

Red cells of abnormal shape

Schistocyte

Recommendation:

Perform microscopic grading of schistocytes. Few/1+ < 1% Mod/2+ 1-2% Many/3+ >2%

Schistocytes are fragments of red blood cells produced by extrinsic mechanical damage within the circulation and are a diagnostic feature of microangiopathic haemolytic anaemia (MAHA)

ICSH RECOMMENDATIONS FOR DETECTION AND QUANTITATION OF SCHISTOCYTES. G. Zini et al. 2012

Sickle cell

Recommendation:

Perform microscopic grading of sickle cells. Few/1+ N/A Mod/2+ 1-2% Many/3+ >2%

Red cells that become crescent or sickle-shaped with pointed ends as a result of polymerization of HbS.

Spherocytes

Recommendation:

Perform microscopic grading of spherocytes. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Spherocytes are of small diameter (<6.5 mm) and are dense spheroidal RBC with a normal or decreased MCV and an absence of central pallor.

Stomatocytes

Recommendation:

Perform microscopic grading of stomatocytes. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Target cells

Recommendation:

Perform microscopic grading of target cells. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Teardrop cell

Recommendation:

Perform microscopic grading of teardrop cells. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Basophilic stippling

Recommendation:

Perform microscopic grading of basophilic stippling. Few/1+ N/A Mod/2+ 5-20% Many/3+ >20%

Howell-jolly bodies

Recommendation:

Perform microscopic grading of howell jolly bodies. Few/1+ N/A Mod/2+ 2-3% Many/3+ >3%

Usually single, small (1mm), dense, perfectly round basophilic inclusions that are fragments of nuclear material (DNA).

Intracellular haemoglobin crystals

Recommendation:

report the presence of hemoglobin crystals when observed

These crystals stain densely, vary in size and have straight edges with pointed ends.

Pappenheimer bodies ferritin aggregates in red cells, visible as multiple basophilic inclusions of variable size, shape and distribution usually in a limited cytoplasmic area.

Recommendation:

Perform microscopic grading of papenheimer bodies. Few/1+ N/A Mod/2+ 2-3% Many/3+ >3%

WHITE BLOOD CELLS

Hypergranulation-neutrophil (toxic granulation) Coarse, purple staining primary (azurophilic) neutrophil cytoplasmic granules which occur as a response to infection and inflammation.

Recommendation:

Perform microscopic grading of toxic granulation. Few/1+ N/A Mod/2+ 4-8% Many/3+ >8%

Hypogranulation-neutrophil Reduced or absent neutrophil granulation causing the cytoplasm of mature neutrophils to appear blue grey.

Recommendation:

Perform microscopic grading of hypogranulation. Few/1+ N/A Mod/2+ 4-8% Many/3+ >8%

vacuolation-neutrophil

Recommendation:

Perform microscopic grading of vacuolation. Few/1+ N/A Mod/2+ 4-8% Many/3+ >8%

Hypersegmented neutrophil

Recommendation:

report the presence of hypersegmented neutrophils when observed

Neutrophil hypersegmentation is defined as any neutrophil having 6 or more lobes or more than 3% of neutrophils having 5 lobes.

Hyposegmented neutrophil (Pelger-Huët neutrophil)

Recommendation:

Hyposegmented neutrophils should be counted and reported as mature segmented neutrophils but with a suitable interpretive comment.

Hyposegmented neutrophils are marked by the failure of normal nuclear lobe development during terminal differentiation and have coarse clumped nuclear chromatin.

Lymphocytes morphologic variants

Synonym: atypical, variant, abnormal, activated, Downey cells, turk cells, immunoblasts, monocytoid lymphocyte . It is recommended that reactive lymphocyte is used to describe lymphocytes with a benign aetiology

It is recommended that abnormal lymphocyte is used to describe lymphocytes with a suspected malignant or clonal aetiology.

It is recommended that lymphoma/hairy /sézary cells are counted as abnormal lymphocytes on first presentation with a detailed description of the cells included in the film comment. After immunophenotyping, the cells may be counted as lymphoma/hairy /sézary cells in the WBC differential

Smudge cells

It is recommended that the automated differential be reported.

The presence of smudge cells should be commented on in the film report

PLATELETS

Giant platelets Giant platelet are larger than normal sized red cells at 10–20 mm in diameter

Recommendation:

Perform microscopic grading of giant platelet. Few/1+ N/A Mod/2+ 11-20% Many/3+ >20%