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Beyond Numbers: A Case in Point
Betsy A. Aird, DVM, PhD
Signalment: 3 year old F/S German Shepherd
History: Increased respiratory rate, tachycardia of 1-2 days duration. Dog
presented at local emergency clinic.
Inside This Issue
Beyond Numbers: A Case in
Point..........................................1
Technician’s Corner..............5
Technician’s Corner
Answers...................................6
PE: T 102.8, panting, possible decreased lung sounds, HR 160, pale mm,
CRT 1-2 sec. No palpable abdominal masses; slightly painful upon palpation of
limbs/joints. Chest, abdominal, joint radiographs and ultrasound declined. The
remaining PE WNL.
Hematological results: obtained from veterinary practice – office laboratory
analyzer:
Test
RBC (x106/µL)
HCT (%)
Hgb (g/dL)
MCV (fL)
MCHC (g/dL)
WBC (x103/µL)
Neutrophils
Lymphs
Monos
Eos
Retics (x103/µL)
PLT (103/µL)
Patient Results
2.99 L
19.8 L
6.6 L
68.2
34.6
14.5
5.2
3.6
4.5 H
1.2
21.3
17 L
Reference Intervals
5.23-8.45
36.9-62.2
13.2-21.1
60.9-74.1
33.2-36.8
5.30-15.82
2.87-11.43
1.00-5.00
0.16-1.12
0.06-1.23
10-110
143-492
Comments:
Possible bands; plt clumps, abnormal scattergram
4DX Combo Test
Positive for Anaplasmosis*
*Diagnosis: Anaplasmosis
BEYOND numbers
RFPT111201
Treatment Plan:
Doxycycline 300 mg/BID
Dexamethasone 20 mg SQ
Send home on medications, keep quiet, recheck with own veterinarian within one
week.
(Continued on page 2)
Results of Patient recheck 10 days later:
PE: Patient remained febrile 103.4, mm pale, anorexic, lethargic, appears slightly painful when handled. Spleen
palpates enlarged. LNs WNL. The remaining PE WNL. Radiographs declined.
Plan: Further treatment pending submission of Complete blood count (CBC) submitted to Marshfield Labs.
CBC results generated by Marshfield Labs:
Test
RBC (x106/uL)
HCT (%)
Hgb (g/dL)
MCV (fL)
MCHC (g/dL)
WBC (x103/µL)
Neutrophils
Lymphs
Monos
Eos
Blasts (x 103/µL)
Retics (x103/µL)
PLT (103/µL)
Comments: See
Pathologist Review
2
Patient Results
3.20 L
24.9 L
7.9 L
73.6
34.5
17.9
1.60 L
2.61
0.36
0.00
13.33 H
8.2 L
Clumped - est 50,000100,00/µL
Examination of
peripheral blood smear:
74% Blasts
No significant
polychromasia or
poikilocytosis;
1+ anisocytosis
Reference Intervals
4.48-8.53
33.0-58.7
10.5-20.1
63.0-78.3
30.8-35.9
4.0-18.2
2.5-15.7
0.30-3.90
0.00-1.40
0.00-1.30
0.00-0.00
10-110
140-540
*Pathologist Review of
peripheral blood smear:
Acute undifferentiated
leukemia; nonregenerative
anemia, mature neutropenia
*Further differentiation of
hematopoietic blast cell type
may be performed via flow
cytometry.
Photomicrogaphs of blood smear from CBC submitted to Marshfield Labs:
Figure 1. (Peripheral blood. Wright Stain; original magnification x 100).
(Continued on page 3)
Figure 2. (Peripheral blood. Wright Stain; original magnification x 500).
Figure 3. (Peripheral blood. Wright Stain; original magnification x 1,000).
Some blood cells exhibit morphologic features resembling lymphoid cell type, while others resemble myeloid cell
type. Further differentiation of an undifferentiated leukemia requires advanced testing such as flow cytometry or
possibly immunocytochemistry.
Diagnosis: Acute Undifferentiated Leukemia (AUL)
(Continued on page 4)
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Discussion:
In the case presented, there was a hint from the original CBC that there were abnormal cells within
blood as noted by the analyzer comment of “abnormal scattergram”. A scattergram is a dot plot which
depicts the distribution of WBCs detected by the analyzer. Abnormal cells can be very difficult for
automated analyzers to appropriately classify; however their presence often results in scattergram
abnormalities that will be flagged. Though all CBCs should include a blood smear review, those with
such abnormalities warrant particularly close evaluation.
Ten days later, the patient had a recheck CBC performed by Marshfield Labs that included
morphologic evaluation of blood smear. At this time, it was noted that 74% of leukocyte population
were blast cells. Further review of the blood smear by a clinical pathologist determined the
hematopoietic blast population to be an Acute Undifferentiated Leukemia (AUL).
Acute undifferentiated leukemia refers to hematopoietic neoplasia in which the blast cell population
is so immature that it cannot be classified morphologically into myeloid (granulocytic, monocytic,
erythroid, megakaryocytic) or lymphoid lineage (see Figures 1-3). Cells lack identifiable morphologic,
ultrastructural, immunologic, and cytochemical markers precluding identification as to specific type.
The diagnosis of an acute leukemia is made by finding a blast cell count of >20-30% in blood and/or
bone marrow with concurrent cytopenias (leukopenia, anemia, or thrombocytopenia). The cells in
acute leukemias are often so immature, that more specific tests other than light microscopy are required
for further cell differentiation. Cytochemical stains and/or immunologic markers are currently used for
this purpose.
Cytochemical stains are often so difficult to interpret, due to nonspecific background staining
and insufficient uptake of the stain by the neoplastic population. Currently immunophenotyping
performed via flow cytometry is the preferred method. Flow cytometric characterization of the
leukemic cell population is based on the expression of specific antibodies on the neoplastic blast cells
when the cells are subjected to a variety of antibody markers. It is important to attempt to differentiate
the leukemic population as to myeloid or lymphoid type since myeloid and lymphoid leukemias are
treated differently and the prognosis for myeloid leukemia is poorer than lymphoid leukemia with
survival times frequently of only a few months.
Clinical signs of acute leukemias in general are of often prominent yet nonspecific including lethargy,
inappetance, and gastrointestinal signs. Physical examination findings may include lymphadenomegaly
or abdominal organomegaly.
It is unknown if the patient was referred for additional evaluation of the leukemic cell population.
Discussion:
This case emphasizes the importance of examining peripheral blood smears when performing a CBC.
Evaluation of the peripheral blood smear is the most important part of a CBC. Eyes can see what
analyzers cannot such as atypical/blast cells, cellular inclusions, toxic change, and RBC morphologic
changes. Consequently, for optimum patient care, all CBCs must include morphological examination
of the blood smear. Blood smears can be made and reviewed in the veterinary office and referred to a
reference laboratory if abnormalities are detected.
At Marshfield Labs, blood smears are evaluated with every CBC. Abnormalities detected by
technologists performing the differential count are referred to a veterinary pathologist for comment.
(Continued on page 5)
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Complete Blood Count w/Differential
Synonym: CBC
Test Code: VCBC
Components: Specimen: RBC, HGB, HCT, MCV, MCH, MCHC, RDW, WBC, PLT, & DIFF
3.0 mL EDTA whole blood (LTT) and 2 peripheral blood smears
Minimum: 1.0 mL EDTA whole blood (LTT)
Cause for Rejection: Clotted or frozen specimen.
Storage: Refrigerate whole blood. Peripheral blood smears are to be kept at room
temperature.
Information: Specimen should be analyzed within 72 hours of collection. Platelet counts are
given only if the platelet result from the analyzer is valid. If result is not valid, an
estimated platelet range is given. If an actual platelet count is needed, the platelet
count will need to be ordered in addition to the CBC.
Available: Daily
Reference Intervals: See “Reference Intervals” section in printed directory.
Method: Automated Hematology Analyzer
Fee: $12.20
Flow cytometry may be performed at: Colorado State University (CSU) for $115. Phone: 970-491-1170.
www.cvmbs.colostate.edu/ns/_docs/departments/mip/cilab/cilab_submission_form.pdf
or
www.dlab.colostate.edu
Please contact them for current submission and billing information.
Technician’s Corner
Betsy A. Aird, DVM, PhD
.
1. Identify the RBC (thin arrow) in the center of the photo below.
2. Describe its predominant morphologic features.
3. What is the significance of these cells when present in increased numbers in the peripheral blood?
4. How does it differ from the RBC in the upper right hand corner (block arrow)?
(Continued on page 6)
Winter 2012
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Canine peripheral blood film. (Wright’s stain; original magnification x 1000).
Technician’s Corner Answers:
1. The RBC in the center of the smear (thin arrow) is an Acanthocyte.
2. This cell is characterized as a spiculated RBC with two or more, irregularly spaced blunted
(thumb-like) projections. It is typically caused by altered lipid:cholesterol ratios in the RBC membrane.
3. Increased numbers of acanthocytes may be associated with hemangiosarcoma (particularly splenic),
glomerulonephropathy, lymphoma and liver disease.
4. The cell in the upper right hand corner is an Echinocyte (crenated RBC). This cell is characterized by
sharp/pointed spicules. The spicules are relatively evenly spaced and of similar size on the cell. It most
commonly is an artifactual change caused by prolonged exposure to EDTA or slow drying. It may also
be present in increased numbers in equines with severe electrolyte abnormalities.
EM photomicrograph of a EM of Echinocyte
RBC Acanthocyte. (Note the (Note more evenly spaced
irregular blunt thumb-like pointed spicules)
projections on the RBC membrane).
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