Blood Cell Identification – Graded · Blood Cell Identification – Graded BCK BCP Referees...

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Blood Cell Identification – Graded

BCK BCP Referees Participants Participants Performance

Identification No. % No. % No. % Evaluation

Neutrophil, segmented or

band 15 93.8 3865 99.0 1715 99.5 Good

Neutrophil with Pelger-Huët

nucleus (acquired or congenital)

1 6.2 - - 1 0.1 Unacceptable

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The arrowed cell is a segmented/band neutrophil and was correctly identified by 93.8% of referees and 99.1% of participants. Segmented neutrophils have condensed nuclear chromatin and segmented or lobated nuclei (2 to 5 lobes typically). Lobes are connected by a thin filament.

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BCK BCP Referees Participants Participants Performance Identification No. % No. % No. % Evaluation

Eosinophil 16 100.0 3897 99.8 1722 99.9 Good

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The arrowed cell is an eosinophil and was correctly identified by 100% of referees and 99.8% of participants. Eosinophils are typically easily recognized due to their characteristic coarse, orange-red granules of uniform size. These granules exhibit a refractile appearance and typically do not overlie the nucleus of the cell. The nucleus is usually segmented into two or more lobes separated by a thin filament, with lobes being of equal size and exhibit the same nuclear characteristics as neutrophilic leukocytes.

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Monocyte 15 93.8 3818 97.8 1680 97.5 Good Macrophage 1 6.2 5 0.1 5 0.3 Unacceptable

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The arrowed cell is a monocyte and was correctly identified by 93.8% of referees and 97.6% of participants. Slightly larger than neutrophils, monocytes are usually round but may exhibit cytoplasmic extensions. The cytoplasm of monocytes is abundant and gray to gray-blue and may contain fine azurophilic granules or vacuoles. The nucleus is usually indented and often kidney-bean shaped with condensed chromatin, but less dense than that of a neutrophil or lymphocyte. Macrophages or histiocytes are found in tissues, rather than peripheral blood.

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BCK BCP Referees Participants Participants Performance Identification No. % No. % No. % Evaluation

Lymphocyte 15 93.8 3751 96.3 1688 98.0 Good nRBC 1 6.2 17 0.4 2 0.1 Unacceptable

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The arrowed cell is a lymphocyte and was correctly identified by 93.8% of referees and 96.8% of participants. A lymphocyte is a small, round to ovoid cell which may range in size from 7 to 15 μm with variable N:C ratios. While most lymphocytes are small with round to oval nuclei, some normal lymphocytes are medium-sized due to an increased amount of cytoplasm. Chromatin is diffusely dense or coarse and clumped. Nucleoli, if present, are small and inconspicuous. In contrast, 6.2% of referees and 0.3% of participants identified the arrowed cell as a nucleated red blood cell. Nucleated red blood cells have dense round nuclei and pink cytoplasm, rather than the basophilic cytoplasm present in the lymphocyte.

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Lymphoma cell 6 37.5 1670 43.2 525 30.7 Good Blast cell 3 18.8 372 9.6 95 5.6 Unacceptable Monocyte, immature

promyelocyte 2 12.5 Unacceptable

Lymphocyte, reactive 5 31.3 1191 30.8 784 45.8 Unacceptable Lymphoblast - - 129 3.3 39 2.3 Unacceptable

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The arrowed cell is a lymphoma cell and was correctly identified by 37.5% of referees and 39.3% of participants. Lymphoma cells may show a variety of morphologic characteristics depending on the underlying type of lymphoma. In this case, the large size of the cell, moderate amount of deeply basophilic cytoplasm, angulated nuclei and prominent nucleoli suggest a large cell lymphoma. These cells can be easily confused with blasts, and additional studies may be necessary to make the correct diagnosis. An accurate clinical history can greatly aid the identification of these cells. In contrast, blast cells have a nucleus with finely reticulated chromatin. Myeloblasts may exhibit a few delicate granules or Auer rods, whereas lymphoblasts often have scant basophilic cytoplasm with nuclei containing finely dispersed chromatin or dense, but not clumped chromatin. See discussion on the following page regarding reactive lymphocytes versus lymphoma cells.

* Not graded due to lack of referee and participant consensus.

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Discussion

Case History

The patient is a 58-year-old male with a history of diffuse large B-cell lymphoma treated 8 months

previously, now thought clinically to be in relapse. Hemoglobin=11.1 g/dL, WBC=11.1 x 109/L,

PLT=383 x 109/L.

This case is an example of a patient with lymphoma, which now involves the peripheral blood. Lymphomas

typically start in lymph nodes or extranodal tissues, spreading to adjacent lymph nodes and usually show a

predilection for hematopoietic organs, including bone marrow and spleen. Blood involvement by lymphoma

typically suggests that the bone marrow is involved by lymphoma. Components of the blood are produced

in the bone marrow; therefore, when lymphoma is in the blood, that usually means it is in the bone

marrow. Exceptions do exist, such as Sezary syndrome (lymphoma is in the blood, but not in the marrow),

which will not be addressed in this discussion. Frequency of peripheral blood involvement by lymphoma

depends on the underlying type of lymphoma (See Table 1 on page 14). In a recent study of lymphomas

involving the bone marrow, the peripheral blood was involved in 29 percent of cases with available

peripheral blood smears for review. In these cases, peripheral blood involvement by lymphoma was

associated with higher white blood cell counts (12,000 vs. 5,480/μL, P= 0.0004 [probability or p value]),

as well as higher absolute lymphocyte counts (6,840 vs. 1,180/μL; P=0.0005) and higher percentage of

lymphocytes (45 vs. 24%, P < 0.0001).1 Unlike acute leukemia, which typically presents with

thrombocytopenia and marked anemia, lymphomatous involvement of the blood may minimally affect the

hemoglobin and platelet counts, if at all. A bone marrow diagnosis of lymphoma should prompt a careful

review of a concurrent peripheral blood smear. In this discussion, features distinguishing reactive

lymphocytes from lymphoma cells will be discussed, as well as the morphologic features of lymphomas

that commonly involve the peripheral blood.

Reactive Lymphocytes versus Lymphoma

Distinguishing reactive lymphocytes from lymphoma cells can be challenging, but a number of key features

should be kept in mind. First, age of the patient is essential. Many of the lymphomas which involve

peripheral blood are much more common in middle aged to elderly adults than children or infants. For

example, certain lymphomas (i.e., Burkitt) are more commonly seen in children. Second, accurate clinical

history can be critical, since any prior diagnosis of lymphoma can aid in the identification of these cells.

Third, a well-prepared and stained peripheral blood smear can be your greatest friend. Old blood and ill

prepared samples can lead to misdiagnoses or simply ‘misses.’ Once you are looking at the peripheral

smear, perform a scan at 10X examining the overall slide before going to higher magnification. Reactive

lymphocytosis will show a wide range of cellular sizes and shapes. The classic example is infectious

mononucleosis (Epstein-Barr viral infection) in which a variety of lymphocytes are seen, ranging from small

lymphocytes with round nuclei and condensed chromatin to reactive lymphocytes with abundant pale blue

cytoplasm, round to oval nuclei and moderately condensed chromatin. (Images 1 and 2 of reactive lymphs

from cases of infectious mononucleosis are seen on the following page.) The cytoplasm of these reactive

lymphocytes may hug adjacent red cells and show a basophilic rim at their margins. Immunoblasts are often

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frequently present, being large lymphocytes with round to oval nuclei containing one or more prominent

nucleoli. The cytoplasm of an immunoblast is abundant and deeply basophilic. Plasmacytoid lymphocytes

may also be seen. In contrast, while reactive lymphocytes are heterogenous, lymphoma cells tend to be

homogenous. A peripheral blood smear may contain a subset of lymphoma cells amidst a background of

small lymphocytes, but those lymphoma cells will resemble one another. Lymphoma cells can exhibit a

variety of morphologic appearances depending on the underlying type of lymphoma, as discussed below.

Lymphoma cells can show various sizes and shapes, ranging from 8 to 30 μm in size and nuclear:cytoplasm

ratios from 3:1 to 7:1, again depending on the type of lymphoma.

Image 1:

Reactive lymphocytes (Infectious mononucleosis)

Image 2:

Reactive lymphocyte (Infectious mononucleosis) (Source: Figure H1-18. In: Glassy EF, ed. Color Atlas of Hematology. Northfield, IL: College of American Pathologists;1998:225.)

Splenic Marginal Zone Lymphoma

The World Health Organization (WHO) recognizes 3 types of marginal zone lymphomas: splenic, nodal and

extranodal. A high frequency of blood involvement by splenic marginal zone lymphoma is well described.1-3

Splenomegaly, often with anemia or thrombocytopenia, is often accompanied by peripheral blood

containing lymphoma cells with ‘villous lymphocytes,’ in which bipolar cytoplasmic projections are present.

These lymphoma cells are larger than typical lymphocytes with abundant pale blue or blue-grey cytoplasm,

round to oval nuclei containing condensed chromatin with usually a single nucleolus. (See Image 3: Splenic

marginal zone lymphoma on the following page.) However, not all cases of splenic marginal zone lymphoma

in the blood will contain lymphoma cells with prominent ‘villi’. These morphologic features often overlap

with hairy cell leukemia. Hairy cells, in contrast have homogenous chromatin and lack nucleoli, with spiky

cytoplasmic projections extending from the entire periphery of the cell. (See Image 4: Hairy cell on the

following page.) Immunophenotyping is often necessary to distinguish these two disorders.

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Image 3: Splenic marginal zone lymphoma

Image 4: Hairy Cell leukemia; ”hairy cell” is to the

left, while a reactive lymphocyte is seen at right.

Mantle Cell Lymphoma

The high frequency of peripheral blood involvement by mantle cell lymphoma is now being recognized.4-6

Frequencies as high as 77 percent peripheral blood involvement have been reported.4 In mantle cell

lymphoma, lymphoid cells may range from small to intermediate sized lymphoid cells with irregular nuclear

contours to large blast-like cells resembling acute leukemia. Typical mantle cell lymphoma cells are larger

than lymphocytes with folded nuclei and a small amount of basophilic cytoplasm. (See Image 5: Mantle

cell lymphoma below.) Nuclei, while condensed contain more reticular chromatin, and may contain a single

prominent nucleolus resembling prolymphocytes. Blastic or blastoid variants of mantle cell lymphoma are

the size of large cell lymphoma cells (20 to 30 μm) and have moderate amount of basophilic cytoplasm,

and nuclei while round to oval, may be indented or convoluted. (See Image 6: Mantle cell lymphoma

blastic variant below.) Chromatin is less condensed, resembling blastic chromatin, although these

lymphoma cells are typically more variable than blasts seen in acute leukemia.

Image 5: Mantle cell lymphoma

Image 6: Mantle cell lymphoma, blastic variant

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Burkitt Lymphoma

Burkitt or Burkitt-like lymphoma cells are morphologically identical to the cells seen in Burkitt leukemia. The

distinction rests on whether there is less than or greater than 25 percent bone marrow involvement,

respectively. The Burkitt cell is moderate in size (10 to 25 μm) with an oval to round nucleus, moderately

coarse chromatin, and 1-3 prominent nucleoli. (See Image 7: Burkitt cell below.) A moderate amount of

deeply basophilic cytoplasm is present and typically contains multiple small vacuoles. Burkitt-like lymphoma

resembles Burkitt lymphoma, but is accompanied by greater pleomorphism in cell size and shape.

Image 7: Burkitt cell

Diffuse Large B-cell Lymphoma

Surprisingly, a relatively high rate (32 percent) of diffuse large B-cell lymphoma in the blood may be seen,

although this is likely underrecognized.1,7 Large cell lymphomas show some of the most abnormal

morphology of the lymphomas. In the past, these lymphomas have been called ‘histiocytic lymphoma’ or

‘reticulum cell sarcoma,’ but now are simply termed large cell lymphoma. Immunophenotypic studies are

necessary to classify whether these lymphomas are of B-, T- or NK-cell origin. They may resemble a

proliferation of immunoblasts with 1-2 prominent nucleoli, or in other cases present with deep convolutions

with occasional nucleoli. These cells are large with small to moderate amounts of deeply basophilic

cytoplasm, occasionally vacuolated, and often show angulated and folded nuclear contours. (See blood cell

images BCK/BCP-11 through 15.) While these cells can be confused with blasts, large cell lymphoma cells

vary in size more than blasts and lack the smooth, even chromatin found in blasts. Additional studies such

as flow cytometry immunophenotyping or bone marrow biopsy may be necessary for correct identification.

Follicular Lymphoma

Follicular lymphoma, when it involves the blood, shows a characteristic morphology. These lymphoma cells

are slightly bigger than normal lymphocytes with a clefted appearance and moderately coarse chromatin.

(See Image 8: Follicular lymphoma on the following page.) Cytoplasm is typically scant, but may be

moderate, and the majority of nuclei show folds and convolutions. Nucleoli may be present. Other types of

lymphoma cells also show angulated nuclei, including mantle cell lymphoma and Sezary cells. Mantle cell

lymphoma cells lack the coarse chromatin of follicular lymphoma and are usually larger in size with gentle

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nuclear folds, not the deep clefts and possible lobes of follicular lymphoma. Sezary cells show convoluted

nuclear membranes with a cerebriform appearance and contain dark, hyperchromatic chromatin lacking

nucleoli typically. (See Image 9: Sezary cell below.) The distinction among the lymphoma types typically

requires immunophenotyping.

Image 8: Follicular lymphoma

Image 9: Sezary cell (Source: Figure HE-11. In: Glassy EF, ed. Color Atlas of Hematology. Northfield, IL: College of American Pathologists;1998:251.)

Table 1. Frequency of Peripheral Blood Involvement by Bone Marrow Lymphoma (adapted from 1)

Type of lymphoma PB disease /total samples

Percentage of PB involvement (%)

Marginal zone lymphomaa 8/10 80

High grade lymphoma, NOSb 1/2 50

Mantle cell lymphoma 11/23 48

Burkitt lymphoma 2/5 40

Diffuse large B-cell lymphoma

12/38 32

Mature T-cell & NK-cell lymphomas

6/20 30

Low grade B-cell lymphoma, NOSb

5/18 28

Follicular lymphoma 9/46 20

Lymphoplasmacytic lymphoma

2/21 10

Small lymphocytic lymphomac

1/10 10

Total 57/197 29 PB=peripheral blood. a. 8 of 9 cases of splenic marginal zone lymphoma showed PB involvement. b. A small number of cases with limited material were classified as high-grade, not otherwise specified and low-grade, not otherwise specified. c. Not meeting criteria for chronic lymphocytic leukemia.

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References

1. Arber DA, George TI. Bone marrow biopsy involvement by non-Hodgkin’s lymphoma. Frequency of lymphoma types, patterns, blood involvement and discordance with other sites in 450 specimens. Am J Surg Pathol. 2005;29:1549-1557.

2. Isaacson PG, Matutes E, Burke M, et al. The histopathology of splenic lymphoma with villous l ymphocytes. Blood. 1994;84:3828-3834. 3. Kent SA, Variakojis D, Peterson LC. Comparative study of marginal zone lymphoma involving bone

marrow. Am J Clin Pathol. 2002;117:698-708. 4. Cohen PL, Kurtin PJ, Donovan KA, et al. Bone marrow and peripheral blood involvement in mantle cell

lymphoma. Br J Haematol. 1998;101:302-310. 5. Matutes E, Parry-Jones N, Brito-Babapulle V, et al. The leukemic presentation of mantle-cell lymphoma:

disease features and prognostic factors in 58 patients. Leuk Lymphoma. 2004;45:2007-2015. 6. Wong K-F, Chan JKC, So JCC, et al. Mantle cell lymphoma in leukemic phase: characterization of its

broad cytologic spectrum with emphasis on the importance of distinction from other chronic lymphoproliferative disorders. Cancer. 1999;86:850-857.

7. Schnitzer B, Kass L. Leukemic phase of reticulum cell sarcoma (histiocytic lymphoma): a clinicopathologic and ultrastructural study. Cancer. 1973;31:547-559.

Tracy I. George, MD Hematology and Clinical Microscopy Committee

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Blood Cell Identification – Ungraded



Blast cell 15 93.8 2183 58.3 819 49.9 Educational Myeloblast 1 6.2 988 26.4 548 33.4 Educational Lymphoblast - - 229 6.1 100 6.1 Educational

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The arrowed cell is a blast (or myeloblast). Myeloblasts are the most immature cells in the myeloid series. The myeloblast is a large cell, 15-20 millimicrons in diameter with a high nuclear to cytoplasmic (N:C ratio), generally round nuclear membranes, a distinct nucleolus and basophilic cytoplasm. The blasts are normally confined to the bone marrow, but may be released into the peripheral blood in malignant and reactive states.

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Neutrophil, promyelocyte 16 100.0 2721 72.9 1117 68.4 Educational Neutrophil, myelocyte - - 315 8.4 155 9.5 Educational Eosinophil, any stage - - 224 6.0 60 3.7 Educational Neutrophil promyelocyte,

abnormal with/without Auer rod(s)

- - 185 5.0 96 5.9 Educational

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The promyelocyte is a round to oval cell that usually is slightly larger than a myeloblast; 12-24 millimicrons in diameter. Promyelocytes have nuclear to cytoplasmic ratios in the range of 5:1 to 3:1, with fine nuclear chromatin and a single prominent nucleolus. In the basophilic cytoplasm, distinct azurophilic (primary) granules are present. Promyelocytes are confined to the bone marrow, except in pathologic states.

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Neutrophil, myelocyte 16 100.0 3093 82.3 1307 79.7 Educational

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The arrowed cell is a myelocyte. Myelocytes are smaller in diameter than the earlier precursors with round to oval nuclei, no nucleoli and chromatin clumping. The cytoplasm is amphophilic with both azurophilic and specific granules present.

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Neutrophil with toxic granules 15 93.8 1594 42.4 722 43.6 Educational Neutrophil, segmented or

band 1 6.2 1485 39.5 657 39.7 Educational

Neutrophil, dysplastic nucleus - - 249 6.6 92 5.6 Educational Neutrophil necrobiosis

(degenerated neutrophil) - - 243 6.5 103 6.2 Educational

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The leukocytes in the slide are neutrophils/neutrophils with toxic granulation. Neutrophils generally constitute 5-10% of peripheral blood leukocytes. Neutrophils have a nuclear to cytoplasmic ratio of 1:3 with dense nuclear chromatin. The nucleus is segmented or lobated with pale cytoplasm which contains specific granules. Toxic granulation is the presence of large purple or dark blue cytoplasmic granules representing primary granules in the cytoplasm of neutrophils. Toxic changes in neutrophils may be seen in a response to infection, burns, trauma or other acute stimuli.

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Neutrophil, toxic (to include

toxic granulation and/or Döhle bodies, and/or toxic vacuolization)

16 100.0 2906 77.2 1157 69.7 Educational

Neutrophil, segmented or band

- - 434 11.5 312 18.8 Educational

Neutrophil with Pelger-Huët nucleus (acquired or congenital)

- - 369 9.8 152 9.2 Educational

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The arrowed cell is a neutrophil with a Döhle body. Neutrophils with cytoplasmic Döhle bodies may be seen as a response to various toxic stimuli. Döhle bodies are single or multiple blue or gray-blue cytoplasmic inclusions of variable size and shape. They may be seen in neutrophils, bands, or metamyelocytes. Döhle bodies may be seen in association with neutrophilic toxic granulation or toxic vacuolization.

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Discussion

Case History

The patient is a 71-year-old Hispanic female with breast cancer. The patient was recently treated and also

received G-CSF that was discontinued a couple of days before the blood smear was obtained.

Additional laboratory data reveals:

• White blood cell count =15.2 x 109/L

• Hemoglobin = 10.0 g/dL

• Platelets = 325 x 109/L

This case demonstrates the peripheral blood cell count and morphologic changes that can be seen in

patients who receive recombinant hematopoietic growth factors. Hematopoietic growth factors are proteins

that bind to receptors on the cell surface with the primary result of activating cellular proliferation and

promoting differentiation and maturation of hematopoietic progenitors. These growth factors are naturally

made in the body. Recombinant DNA technology has allowed production of synthetic growth factors,

which are now available for use in patients with cytopenias. While different growth factors have varied

affects on different cell systems, in general they stimulate lymphocytic, hematopoietic and non-

hematopoietic cell lineages.

The following is a list of the growth factors that are most commonly used clinically:

Granulocyte/colony stimulating factor (G-CSF)

Granulocyte/monocyte colony stimulating factor (GM-CSF)

Interleukin (IL-3)

Erythropoietin

Thrombopoietin

Granulocyte colony stimulating factor (G-CSF) regulates the proliferation and maturation of neutrophilic

granulocytic progenitors by binding to receptors on committed granulocyte precursors. G-CSF also

increases the functionality of granulocytes by enhancing granulocytic, monocytic and macrophage cells

involved in antigen presentation and cell-mediated immunity. The maturation time of myeloid progenitors in

the bone marrow is shortened from 5 days to as little as one day. The gene for G-CSF is located on

chromosome 17 (17q11-23).

Granulocyte/monocyte colony stimulating factor (GM-CSF) is a potent stimulus for the growth of

granulocytic, erythrocytic, macrophage and megakaryocytic progenitors. The GM-CSF receptor is expressed

on granulocyte, erythrocyte, megakaryocyte and macrophage progenitor cells, as well as mature

neutrophils, monocytes, macrophages, dendritic cells, plasma cells, certain T-lymphocytes, and vascular

endothelial cells. Although GM-CSF has greater activity on immature progenitors than does G-CSF, its

proliferative effects are less significant than those of interleukin 3 (IL-3). GM-CSF also enhances the

function of mature granulocytic cells and monocytes. The gene for GM-CSF is located on chromosome 5

(5q23-31).

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Interleukin-3 also known as multi-CSF stimulates the bone marrow stem cells and thereby the growth of

granulocytes and monocytes, and to a lesser degree megakaryocytic and erythroid precursors. The gene for

IL-3 is located on the long arm of chromosome 5.

Erythropoietin (EPO) is the primary regulator for erythropoiesis. EPO stimulates and induces maturation of

colony forming units erythroid (CFU-E) and a subset of the burst-forming units erythroid (BFU-E). The gene

for EPO is located on chromosome 7.

Thrombopoietin is a primary stimulator of megakaryocytic proliferation, causing a significant rise in the

platelet count.

All of the growth factors work by interacting with specific receptors on target cells. For example:

EPO binds to EPO receptors on committed red blood cell precursors

GM-CSF and IL-3 bind to receptors on early granulocyte precursors

G-CSF binds to receptors on slightly more mature committed granulocytic precursors

Due to the diversity in the clinical indications for using hematopoietic growth factors, it is important for

laboratory professionals and pathologists to recognize the peripheral blood and bone marrow findings in

patients on such factors. Although there is some variability in the peripheral blood findings related to which

growth factor the patient has received, peripheral neutrophilia is expected. The growth factors utilize three

mechanisms that lead to the increase in neutrophils. These include:

demargination of neutrophils from the marginated pool

mobilization of the maturation-storage bone marrow compartment

increased neutrophil production

As a response, the granulocytic series is frequently left-shifted with myeloid elements including blasts,

promyelocytes, myelocytes and metamyelocytes present. Challenges BCK/BCP-16, BCK/BCP-17 and

BCK/BCP-18 demonstrate a blast (myeloblast), promyelocyte and myelocyte, respectively, which were

identified in the peripheral blood of this patient.

In addition to the increased number of mature and immature granulocytic elements, toxic changes are

frequently seen. Toxic granulation, Döhle bodies and toxic vacuoles, all changes more commonly associated

with infection, can be seen as a response to hematopoietic growth factors. Challenges BCK/BCP-19 and

BCK/BCP-20 exhibit a neutrophil with toxic granulation and a neutrophil with a Döhle body, respectively.

The two major differential diagnostic categories of a peripheral blood granulocytosis include reactive

neutrophilia and neoplastic neutrophilia (myeloproliferative disorders). Reactive neutrophilia may be due to a

infectious process; as a response to drug or hormonal therapy; in patients with burns, acute trauma or

myocardial infarction; in inflammatory disorders such as collagen vascular or other autoimmune disorders;

as a response to stress or severe exercise; in pregnancy; in uremic patients; and in patients with acute

hemorrhage or hemolysis. In the myeloproliferative disorders the white blood cell count is usually more

pronounced than in reactive processes. Chronic myelogenous leukemia (CML) is the most common

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myeloproliferative disorder, with essential thrombocythemia, polycythemia vera, myelofibrosis and chronic

myeloproliferative disorder, non-specified completing the list.

In some patients a peripheral monocytosis and circulating nucleated red blood cells are also identified as a

response to growth factors. Less commonly, dyspoietic myeloid elements are seen as a response to the

synthetic growth factors. The dyspoietic features can include cells, which exhibit nuclear-cytoplasmic

dyssynchrony and nuclear segmentation defects.

In patients with a known diagnosis of acute myeloid leukemia receiving chemotherapy, the distinction of

persistent or relapsed leukemia from regenerating bone marrow related to growth factors can be quite

challenging. The findings of blasts with Auer rods, the presence of more differentiated myeloid elements,

and the presence of erythroid or megakaryocytic elements as would be expected in regeneration, can be

helpful in this distinction. However, sometimes ancillary studies, to include cytogenetic analysis and flow

cytometric analysis may be necessary to confirm the absence of leukemic blasts.

In patients with a known diagnosis of the myelodysplastic syndrome, administration of synthetic growth

factor may lead to a left-shift in the myeloid series, raising the concern of transformation of the

myelodysplastic syndrome into acute leukemia. Close attention to morphologic details, in conjunction with

cytogenetic analysis and flow cytometric analysis may be necessary to make this distinction.

Examination of the bone marrow of the patient receiving growth factors reveals panhyperplasia, involving

all three cell lines. However, myeloid hyperplasia is most pronounced and can be significantly left-shifted.

As the duration of therapy persists, the left-shifted myelopoiesis becomes less pronounced and the myeloid

to erythroid ratio typically normalizes.

Clinical indications for use of the hematopoietic growth factors have been an area of intense study since

their discovery in the mid 1990’s. In addition to reviewing patient’s peripheral blood and bone marrow

responses to the growth factors, the incidence of neutropenic fever, rate of infections, duration of

hospitalization, morbidity and mortality have all been outcomes, which have been reviewed in patients

receiving growth factors. In 1994 the American Society of Clinical Oncology issued recommendations for

the use of hematopoietic colony-stimulating factors. These clinical practice guidelines have been reviewed

with the most recent guidelines released in November 2003. The current recommendations are that colony

stimulating factors are recommended in some situations:

1. To reduce the likelihood of febrile neutropenia when the expected incidence is >40 percent

2. After documented febrile neutropenia in a prior chemotherapy cycle to avoid infectious complications

3. To maintain dose intensity in subsequent treatment cycles when chemotherapy dose reduction is not appropriate

4. After high-dose chemotherapy with autologous progenitor cell transplantation

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It is not recommended, based on current evidence, that colony stimulating factors should routinely be used

in patients with neutropenia who are afebrile. The therapeutic use of CSF in addition to antibiotics at the

onset of febrile neutropenia should be reserved for patients at high risk for septic complications. It is not

recommended that CSF be used concurrently with chemotherapy and radiation therapy. The clinical

indications for use of CSF in the pediatric population are similar. While it is recognized that administering

growth factors can significantly shorten the duration of severe neutropenia, however, this does not always

lead to shortened hospital stays or decreased rate of infection.

Recombinant erythropoietin (epoetin) is recommended in patients with chronic anemias to enhance

erythrocyte production. Epoetin is recommended for patients with a chemotherapy-associated anemia who

have a hemoglobin < 10.0 g/dL. In some chemotherapy patients, epoetin may be given when the anemia is

less severe (<12.0 but >10.0 g/dL). Epoetin is also recommended for patients with chronic renal disease

or other chronic disease causing significant anemia.

The side effects, adverse reactions, complications of growth factors are generally mild and the drugs are

well tolerated. Diarrhea and fluid retention may be seen as a side effect in patients receiving erythropoietin.

GM-CSF has a risk of fever, headaches, skin rash, pericardial effusions and medullary bone pain. Medullary

bone pain is the most common acute adverse reaction seen in the pediatric population. Bone pain, skin

rash, allergic reactions and splenomegaly may be seen in patients receiving G-CSF.

Summary

As hematopoietic growth factors are frequently used in patients receiving chemotherapy, in patients with

the myelodysplastic syndrome, and in patients with chronic anemias, it is important for those in laboratory

medicine to recognize the peripheral blood and bone marrow findings related to these agents.

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References

1. Sung L, Nathan PC, Lange B, Beyene J, Buchanan GR. Prophylactic granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor decrease febrile neutropenia after chemotherapy in children with cancer: A meta-analysis of randomized controlled trials. J Clin Onc. 2004 Aug 15;22(16):3350-3356.

2. American Society of Clinical Oncology. Use of hematopoietic colony-stimulating factors: evidence-based, practice guidelines. J Clin Oncol. 2003 Nov 20;12:2471-2508.

3. American Society of Clinical Oncology. Recommendations for the use of hematopoietic colony-stimulating factors: evidence-based, clinical practice guidelines. J Clin Oncol. 1994;12:2471-2508.

4. Hoelzer D. Hematopoietic growth factors-Not whether, but when and where. N Engl J Med. 1997 Jun 19;336(25):1822-1824.

5. Wagner LM, Furman WL. Haemopoietic growth factors in paediatric oncology. Paediatr Drugs. 2001;3(3):195-217.

6. Hartmann LC, Tschetter K, Habermann TM, et al. Granulocyte colon-stimulating factor in severe chemotherapy-induced afebrile neutropenia. N Engl J Med. 1997 Jun 19;336(25):1776-1780.

7. Schmitz LL, McClure JS, Litz CE, et al. Morphologic and quantitative changes in blood and marrow cells following growth factor therapy. Am J Clin Pathol. 1994 Jan;101(1):67-75.

8. Harris AC, Todd WM, Hackney MH, Ben-Ezra J. Bone marrow changes associated with recombinant granulocyte-macrophage and granulocyte colon-stimulating factors. Discrimination of granulocytic regeneration. Arch Pathol Lab Med. 1994 Jun;118(6):624-629.

9. Orazi A, Gordon MS, John K, Sledge G Jr, Neiman RS, Hoffman R. In vivo effects of recombinant human stem cell factor treatment. Am J Clin Pathol. 1995 Feb;103(2):177-184.

10. Meyerson H, Farhi DC, Rosenthal NS. Transient increase in blasts mimicking acute leukemia and progressing myelodysplasia in patients receiving growth factor. Am J Clin Pathol. 1998 Jun;109(6):675-681.

11. Pitrak DL. Effects of granulocyte colony-stimulating factor and granulocyte macrophage colony-stimulating factor on the bactericidal functions of neutrophils. Curr Opin Hematol. 1997 May;4(3):183-190.

12. Glaspy JA, Golde DW. Clinical applications of myeloid growth factors. Semin Hematol. 1989 Apr;26(2 Suppl 2):14-17.

13. Rizzo JD, Lichtin AE, Woolf SH, et al. Use of epoetin in patients with cancer: evidence-based clinical practice guidelines of the American Society of Clinical Oncology and the American Society of Hematology. J Clin Oncol. 2002 Oct;20(19):4083-4107.

14. Kaushansky K. Lineage – Specific hematopoietic growth factors. N Engl J Med. 2006 May 11;354(19): 2034-2045.

Deborah A. Perry, MD

Hematology and Clinical Microscopy Resource Committee

Blood Cell Identification – Graded · Blood Cell Identification – Graded BCK BCP Referees...

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Transcript of Blood Cell Identification – Graded · Blood Cell Identification – Graded BCK BCP Referees...