Polycythemia/Leukemia Flashcards
What is polycythemia?
Increased red cell concentration
What are examples of relative polycythemia?
Hemoconcentration
- Dehydrationg
- Fluid shifts - hemorrhagic colitis; not systemically dehydrated
Redistribution of red cells chillin in the spleen
- excitement
- exercise - horses off the track
What are examples of absolute polycythemia?
Increased erythropoietin
- Appropriate - chronic hypoxia (measure 02a)
- Inapproproate EPO secretion (renal cysts, tumors) - cells that make EPO are hypoxic and assume the rest of the body is too.
Primary - Polycythemia vera (myeloproliferative disorder)
A 4 year old dog presents for lethargy and vomiting. PCV is high at 75% and protein is high at 9.8 (6-8). What is a probable cause for the polycythemia?
Dehydration due to vomiting (relative)
What is the most likely cause of increased albumin levels?
Dehydration
A 4 year old dog with BUN 145 (7-28), Creat 6.5 (0.9-1.7), and Phos 12.2 (2.8-6.1) has a urine SG of 1.011, indicating that glomerular filtration is normal. The urine sediment shows RBCs and 6-sided crystals. What is the likely cause of the high renal values?
Ethylene glycol poisoning
Calcium oxalate crystals are seen in antifreeze poisoning. Metabolites damage renal tubular epithelial cells, which explains the renal values on the chemistry. Increased calcium levels lead to formation of the crystals.
A dog presents for lethargy and PU/PD. The PCV is 69% and protein is normal. Arterial O2 is normal, but the erythropoietin level is increased. What is the likely cause of increased PCV?
Kidney mass or cyst.
*Absolute polycythemia with inappropriate EPO secretion
A 9 year old dog presents for lethargy and PU/PD. She has a PCV of 71% and the protein level is normal. You test arterial O2 and erythropoietin and both are normal. A blood film shows normal looking erythrocytes with normal maturation. What is the likely cause of the increased PCV?
Polycythemia vera
A 7 year old dog with heart disease presents for lethargy and dyspnea. He has a PCV of 62% and normal protein level. Reticulocyte count is increased at 100 (0-60). Arterial O2 is decreased and erythropoietin is increased. What is the cause of the polycythemia in this dog?
Chronic hypoxia
*Absolute polycythemia with appropriate EPO secretion
What is difficult about diagnosing stage 5 lymphomas?
Stage 5 lymphomas are leukemic, which makes them hard to distinguish from a leukemia
Blood tests on a cat show marked neutrophilia and normal maturation. How can neutrophilia from inflammation be distinguished from neutrophilia due to a chronic myeloproliferative disease?
If neutrophil counts are greater than 100,000/uL it’s a chronic myeloproliferative disease.
What number of lymphocytes indicates a lymphocytic leukemia in any species?
Greater than 35,000/uL
What is the most reliable way to identify cell types in order to classify lymphoid vs myeloid proliferations?
Monoclonal antibody binding to antigens
What test is used to identify a clonal, neoplastic population of cells, and differentiates non-neoplastic lymphoproliferative disorders?
PCR (PARR)
A blood film on a dog shows numerous lymphoblasts. What is the prognosis?
Poor.
This is acute lymphoblastic leukemia. MST is 9 days for both ALL and AML.
A blood smear on a dog shows numerous mature, well differentiated neutrophils. The neutrophil count is over 100,000/uL, so you know this isn’t just an infammatory response. What is the prognosis?
Not so bad. Dogs with chronic leukemias can live for years.
B or T cell neoplasias involving the bone marrow or blood are called:
lymphocytic leukemias
B or T cell neoplasias that are confined to solid tissue are known as:
Lymphomas
What are 2 important features of lymphocytosis that can help differentiate the process?
Magnitude and morphology
Although antigenic stimulation is a rare cause of lymphocytosis in small animals, what is an exception?
Canine Ehrlichiosis
*Large granular lymphocytes and polyclonal gammopathy will likely be present in this case.
A differential cell count on a dog shows a greater than 15,000/uL lymphocyte concentration. You do a 4Dx test and the patient is negative for tick borne disease. What is your diagnosis?
Likely leukemia
Acute lymphocytic leukemias are more common in what grouping of cats?
Younger, FeLV positive cats
A dog presents for lethargy and swollen lymph nodes. MM are pale and the spleen feels large on palpation. You take a bone marrow aspirate and see many small, mature lymphocytes. Considering the species, what type of leukemia is most likely?
Chronic lymphocytic leukemia
T/F: When considering diagnosis of a multiple myeloma, it is easiest to find proliferation of plasma cells on a blood film.
FALSE
Multiple myelomas occasionally release into the blood, but only in small numbers. Diagnose with a bone marrow aspirate.
A bone marrow aspirate on a sick dog. What is the disease?
Multiple myeloma (neoplastic proliferation of plasma cells)
A dog presents with lameness, epistaxis, and PU/PD. A fundic exam shows retinal hemorrhages, and xrays show lytic lesions in the bones. What laboratory finding will help lead you to your diagnosis?
Monoclonal or biclonal gammopathy
*This is Multiple Myeloma. Increased proteins will either be IgG or IgA. Bence Jones proteins may also be found in the urine.
A FeLV positive cat has dysplastic myeloid cells on his blood smear. What disease is this a precursor to?
Leukemia
*Myeloid dysplasia is often pre-leukemic and is found in dogs and cats (FeLV or FIV positive), and rarely in horses.
Chronic myeloproliferative neoplasms can be difficult to distinguish from _______.
Hyperplasia
A sick, anemic dog comes in for routine bloodwork and on the CBC diff, neutrophil counts are over 100,000/uL with a left shift. A blood film shows cells with hypersegmented nuclei and giant metamyelocytes. What is the diagnosis?
Chronic granulocytic (myelogenous) leukemia
In a dog with chronic granulocytic leukemia, what are the limitations of using a bone marrow biopsy for diagnosis?
Orderliness of maturation may appear disrupted with an inflammatory process, making it difficult to differentiate from a neoplastic process with incomplete maturation.
How can we make a definitive diagnosis of chronic granulocytic leukemia, and effectively differentiate it from inflammatory disease?
Eventually you will see a disorderly left shift and “blast crisis”. Patients with leukemia are also much more anemic than patients with inflammatory disease.
