Polycythemia and Leukemia Flashcards
What is polycythemia
Increased red cell concentration (increased PCV)
Relative polycythemia
- not an absolute increase
- not that the red cell mass has increased but that the water portion/ plasma has decreased for some reason
types of relative polycythemia
- Hemoconcentration (dehydration and fluid shifts)
- Redistribution (excitement, exercise)
Absolute polycythemia
There is an actual increase in red cell production
types of absolute polycythemia
- increased erythropoietin
- appropriate (chronic hypoxia)
- inappropriate (renal cysts, tumors)
- primary (polycythemia vera)
- myeloproliferative disorders
an increased PCV and TP are indicative of…
dehydration (relative polycythemia)
Possible Dx for macrocytic polycythemia, normal TP, EPO and arterial O2 Normal
polycythemia vera
DDx for decreased arterial oxygen and increased EPO
PCV usually isn’t sky high
Dx: Hypoxemia
Heart function vs Lung Function (Imaging to differentiate)
Leukemia
neoplastic cells in blood or bone marrow (spleen should also be included-some forms of lymphoid leukemia and T cell leukemia cells are produced solely in the spleen)
types of leukemia
- Lymphoproliferative Disorders
- Myeloid neoplasms (Myeloproliferative disorders)
lymphoma
Starts in the tissue can ultimately get a leukemia
with lymphoma
Ways leukemias are classified
- Lymphoid vs myeloid
- Immunophenotype
- Acute vs chronic
- Cell morphology (small, large, LGL, etc)
- By number of circulating cells (aleukemic, subleukemic, leukemic)
- Leukemias may arise in bone marrow or spleen, but Stage V lymphomas are leukemic and these may be difficult to distinguish if they present late in disease
Immunophenotyping Leukemias
The kinds of antigens the cells have on their membrane, recognized by antibodies against those antigens. The kinds of cell markers are very important for prognosis
Acute vs Chronic Leukemia refers to
patient survival time
- Acute- effects immature cells (bone marrow and peripheral blood- blasts, lymphoblasts/myeloblasts)
- Chronic- typical cells look mature
Acute Leukemia types
- Acute Lymphoblastic Leukemia (almost always this when acute)
- Acute Myelogenous Leukemia
Chronic Leukemia types
- Chronic lymphocytic leukemia
- B-cell
- T-cell
- Chronic myeloproliferative
Chronic Myeloproliferative leukemia
Common in people rare in dogs and cats
Can be difficult to distinguish from inflammatory leukograms: neutrophils are maturing and they can be orderly, become suspicious when neutrophil count is greater than 100,000
Identification of cell types to classify lymphoid vs myeloid
- Morphologic appearance
- Cytochemical staining properties
- Electron microscopic appearance
- Monoclonal antibody binding to antigens
CD 3, 4, 5, 8
T cells leukemias
CD 21, 79a
B cell leukemias
Simple Classification: Lymphoproliferative
- Lymphoblastic leukemia
- Lymphocytic leukemia
- Plasma cell leukemia (multiple myeloma)
Simple Classification: Myeloproliferative
- Undifferentiated leukemia
- Granulocytic leukemia
- Monocytic leukemia
- Myelomonocytic leukemia
- Erythroid leukemia (erythremic myelosis)
- Megakaryocytic leukemia
PCR detects
- antigen receptor rearrangements
- used to identify a clonal, neoplastic population of cells
- referred to as “PARR”
PCR/ PARR differentiates
non neoplastic lymphoproliferative disorders from those that are neoplastic
Ehrlichia*
Acute leukemia
- neoplastic cells immature
- Survival time is usually very short: MST – 9 days for ALL and AML (range, 1-120 days)
Chronic leukemia
- “mature” well-differentiated cells predominate
- patient survival time is usually long
Acute Lymphoblastic Leukemia (ALL)
- Need to differentiate from Stage V lymphoma
- “65% of dogs presenting with multicentric lymphoma are leukemic.”
- 50% of dogs with ALL have lymphadenopathy
how to determine if lymphoblastic leukemia on cytology
- Use neutrophil for size comparison ( should be around the same size)
- Larger size and presence of nucleoli tells us they are immature cells or lymphoblast
- Cytoplasm will break off and get cytoplasmic fragments (almost look like platelets) - lymphoglandular bodies- Help to distinguish in cytology
Lymphoid cells rupture easily
T/F in cases of leukemia, animals can present with anemia, neutropenia, and thrombocytopenia
True: more prevalent in animals with acute leukemias
clinical signs of acute leukemia
Due to lack of normal hematopoietic cells or to infiltration of organs.
- Pale mucous membranes
- Splenomegaly
- Hepatomegaly
- Lethargy
- Weight loss
CBC abnormalities – Acute leukemias
- Anemia
- Thrombocytopenia
- Leukocytosis
- Mean TNCC – 98,000/μl
- Immature cells in blood
Prognosis- ALL
Poor
- Clinical course is usually rapid, progressive, and poorly responsive to therapy.
- Cats are usually younger and Fe-LV positive.
Acute Myeloid Leukemia
must have 20% or greater blast cells in the bone marrow.
But % of blasts in blood is variable
T/F Very poorly differentiated myelogenous or myelomonocytic leukemia cannot be differentiated, based on morphology, from lymphoid leukemia
True
What is undifferentiated leukemia
Almost all cells in bone marrow are immature cells that cannot be classified based on morphology or cytochemistry.
Has features of both erythroid and myeloid Leukemia
how do you classify undifferentiated leukemia
immunophenotyping
Myeloblastic leukemia (M1)
> 90% Blasts in BM;
Myeloblastic leukemia with differentation (M2)
20% blasts but 10% differentiated granulocytes
Often many promyelocytes
T/F Immune mediated neutropenia can appear similar to granulocytic leukemia
True! When we do a bone marrow aspirate, everything later is being destroyed by antibodies directed against its own neutrophils so what you have left are blasts. Occasionally missed diagnosed as leukemias but get better on steroids
Myelomonocytic leukemia (M4)
Myeloblasts and monoblasts >20% in BM
Monocytes and granulocytes > 20%
Monocytic leukemia (M5)
M5a Promonocytes and monoblasts; >80% of non erythroid cells
M5b >20% to
Erythroleukemia (M6)
Erythroid > 50%, myeloblasts and monoblasts
Megakaryoblastic leukemia (M7)
> 20% megakaryoblasts, also in blood
Increased megakaryocytes
May need immunocytochemistry to detect reactivity for factor VII-related antigen and platelet glycoprotein IIIa
Thrombocytopenia or thrombocytosis
Chronic lymphocytic leukemia
Lymphocytes are small and appear well differentiated.
More common in dogs.
Must be differentiated from other causes of lymphocytosis.
>35,000 lymphs, it is leukemia.
T/F: T-cell CLLs are more common in dogs and cats than B-cell CLLs
true
where do T-cells tend to proliferate
the spleen
DDx of CLL in cats
excitement lymphocytosis (usually not greater than 20,000)
Bartonella henselae (“cat scratch fever”)
DDx of CLL in dogs
Chronic ehrlichiosis (often see large granular lymphocytes)
Excitement lymphocytosis rare
Rarely hypoadrenocorticism
Clinical signs of CLL
May be asymptomatic (diagnose during wellness exam)
lethargy, anorexia, pale mucous membranes, lymphadenopathy, splenomegaly, hepatomegaly possible
Laboratory Findings for CLL
Lymphocytosis ( slightly increased to > 300,000/μl)
Maybe anemia thrombocytopenia
Increased small lymphs in BM
Rarely monoclonal gammopathy
Cats are usually Fe-LV neg
T/F immunophenotyping is not helpful for prognosis
False
T/F Myelodysplastic syndromes have variable manifestations, usually with subtle morphologic abnormalities
True
Myelodysplastic syndromes-cytopenia
single or in combination, including non- regeneratve anemia, neutropenia, and/or thrombocytenia.
Myelodysplastic syndromes-marrow
hypocellular, of normal cellularity or hypercellular.
Myelodysplasia
Often pre-leukemic
Reported in dogs, cats, rarely horses
Usually FeLV induced in cats
Chronic myeloproliferative neoplasms
Rare
Difficult to distinguish from hyperplasia
Chronic granulocytic (myelogenous) leukemia
More common in dogs than in cats
marked neutrophilia, left shift, and often monocytosis.
Hypersegmented nuclei, giant metamyelocytes, bands
DDx Chronic granulocytic (myelogenous) leukemia
Differentiated from MDS by marked leukocytosis.
Inflammatory responses (“leukemoid reactions”)
Marrow exam may not be helpful as orderliness of maturation may appear disrupted with inflammation
Definitive diagnosis of Chronic granulocytic (myelogenous) leukemia
Eventually develop disorderly left shift and “blast crisis”
Usually much more anemic than patients with inflammatory disease
Eosinophilic leukemia
Rare, primarily in FeLV-negative cats
Eosinophilia, immature eosinoiphils in blood, eosinophil predominance in marrow, eosinophil infiltration of organs
Clinical signs of Eosinophilic leukemia
similar to other MPDs but also include thickened bowel loops, diarrhea, vomiting due to eosinophil infiltration of intestine.
T/F Hydroxyurea and prednisone may prolong survival of patients with eosinophilic leukemia
true
Chronic basophilic leukemia
Very rare
Basophilia, orderly left shift, maybe thrombocytosis, organ infiltration
Differentiate from mast cell leukemia
Essential thrombocythemia
Very very rare
Platelets > 1,000,000/μl. Giant forms.
Increased megakaryocytes in marrow
DDx Essential thrombocythemia
iron deficiency anemia, inflammation, antineoplastic drug therapy, corticosteroids, neoplasia, all of which can cause thrombocytosis.
