ISSUE07

ISSUE

November
2020

This issue

Last Month’sSlides
October 2020 Slide
Summaries

Last Month’s Slides P.1
Digital Case study P.1
Myeloproliferative Disorders, Part 1 P.2
Red Cell Characteristics in Nature P.3
Bibliography P.3

Monthly Digital Case study
October 2020 Slide 6
Presentation

Slide 1
Normal film

Slide 2
Normal film

Slide 3
A Leukocytosis

Slide 4
Myelofibrosis Patient

Female patient, 64 years old. The patient is hospitalised and on a continual care unit.

FBC Results
WBC 19.4 (10^3/mm3)
RBC 2.63* (10^6/mm3)
HGB 7.8* (g/L)
HCT 24.4* (%)
MCV 93 (fL)
MCH 29.8 (pg)
MCHC 32.2 (g/dL)
PLT 1074* (10^3/mm3)

Neutrophils 65.9%
Lymphocytes 15.2%
Monocytes 6.1%%
Eosinophils 4.5%
Basophils
1.5%

Slide review
Film shows platelet clusters, anisocytosis
and hypochromic red cells.

Slide 5
Platelet anisocytosis and plateletclumps seen

Slide 6
Myeloproliferative Syndrome,essential thrombocytopenia andplatelet clumps seen.

Diagnosis
Further testing for Bcr_alb mutation to confirm
if the patient has Chronic Myeloid Leukaemia(CML) or possibly a specific form of acutelymphoblastic leukaemia.

Monthly Morphology
Quiz
Look closely at the film
below:

Myeloproliferative Disorders
Part 1Introduction
Chronic myeloproliferative disorders (also known as myeloproliferative neoplasms) area unique group of hematopoietic stem cell disorders that have common mutations
which continuously activate. JAK2 (Janus kinase 2), is an enzyme which usuallystimulates the production of red blood cells, white blood cells (granulocytes,monocytes, basophils and eosinophils) and platelets. JAK2 is usually only activatedwhen additional blood cell production is required. Because the blood cells in the
myeloproliferative disorders are usually normal in appearance, these disorders mimicclinically benign or reactive blood conditions in which blood production is increased
because of stimuli such as hypoxia, inflammation or infection as well as certain
malignancies such as chronic myelogenous leukemia and myelodysplasia.

What do you notice about
this film?

Last month’s cells:

Polycythemia vera
This is the most common myeloproliferative disorder. It is characterised by theexcessive production of normal red blood cells and may result in excessive productionof white blood cells and platelets over time. Symptoms include itching and classically aburning sensation in hands and feet known as erythromyalgia. This is caused by anincreased platelet count, or increased stickiness of the platelets causing tiny clots.
Patients with PV are susceptible to thrombosis due to red blood cell-induced hyper
viscosity; heart attack, stroke and DVT are often an early indication.
Diagnosis may include splenomegaly or enlarged liver due to migration of the involved
hematopoietic stem cells from the marrow (extramedullary hematopoiesis). Laboratory
findings would include raised Hb and Hct, possible raised WBC and Platelet count and araised ESR. A mutation in the JAK2 kinase is strongly associated with PV, and this test
would be helpful in the diagnosis and target therapy for the future.

Hypereosinophilic Syndrome
The slide shows May-Hegglin
Anomaly (MHA) from a patient
recently diagnosed with MYH9
genetic disorder with a previous
history of unexplained bruising.
MHA is a rare, inherited, blood
plateletdisorderwhichisautosomal dominant. This disorder
is indicated by degrees ofthrombocytopenia which may beassociated with purpura andbleeding; abnormally large andmisshapen platelets containing few
granules; and large, well-defined,basophilic, cytoplasmic inclusion
bodies in granulocytes that
resemble Döhle bodies.

This is a rare disorder due to mutations in proteins
which stimulate eosinophil production. Eosinophils,
when inappropriately activated, infiltrate tissue andrelease proteins and inflammatory mediators thatdamage organs such as the heart, lungs intestines,
nervous system and blood vessels as well as causingorgan enlargement. Symptoms include skin lesions,pulmonary disease, neuropathy and atopic eczema.
Film from Hypereosinophilic patient
If left untreated, HES is progressive and fatal. In order to correctly diagnose, the mostimportant being the blood test and film, where an eosinophil count >1.5x109/L. The
blood film can sometimes show normal (although raised) eosinophils but morphologicalabnormalities, such as less granulation and size can be noted.
Treatment to reduce eosinophil levels consists of Corticosteroids. Occasionallysplenectomy and prosthetic heart valves may be indicated.

Bibliography

Red Cells characteristics
in nature

Hoffbrand’s Essential
Haematology 7th edition
Wiley Blackwell

Normal human red cells are characterised by being biconcave discs with no nucleus
and a normal Mean Cell Volume (MCV) of 80 – 100 fl. This is not the same in thenatural world with the MCV being totally different and in the case of birds, reptiles
and fish contain a nucleus. Amphibian red cells are massive and may be up to 500 fl involume whereas in goats the mean MCV is approx. 20 fL. The red cell shape is also
different e.g. camels having elliptical cells which may protect from the effect ofdehydration and some species of Deer display sickle shaped red cells. See tables
below for examples of MCV amongst species:
Species
MCV (fl)SpeciesDog
60 - 72Goat

Cat
39 - 50
Pig

Horse
36 - 52
Mouse

Cow
40 - 60
Rat

Sheep
25 - 40
RabbitCamel
20 - 28
Penguin

MCV (fl)16 -2550 -5642 - 56

56 - 62

65 – 76

238

Species

Buzzard

Eagle

Owl

MCV (fL)

151 -171160 - 184

145 - 216

SpeciesParrotOstrichIguanaMCV (fL)

137 - 155174

163 - 305

Observations on theSizes and Shapes of theRed Corpuscles of theBlood of Vertebrates. G
Gulliver 1875
Essentials of Veterinary
Haematology . N.C. Jain
Clinical Avian Medicine
Vol II, Chapter 22,
Diagnostic Haematology.
J Samour

Editorial Team
Kelly Duffy
Andrew Fisher

See below for an illustrative guide to red cells volume in various animals

About usThis Month’s Top Morphology Tip
Always check the date on a sample before making afilm. EDTA changes in a sample can be seen as littleas <24hrs post venepuncture. Samples collected in
EDTA and stored at room temperature can show
degenerative changes in leucocyte and erythrocyte
morphology. Changes that occur due to a delay inslide making can result in misinterpretation of theblood film, e.g. -segmented neutrophils could be
misidentified as young neutrophils, with thedifferential showing a left shift - Crenated red cells(see right) can resemble acanthocytes.

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