Chapter 19 Leukaemia Flashcards
What is leukemia?
A condition where there are tumor cells of hematopoietic origin in the blood and/or bone marrow.
How is leukemia classified in horses?
Based on cell of origin (lymphoid or myeloid) and degree of differentiation (acute or chronic).
What are the two main criteria for classifying leukemias?
Cell of origin and degree of differentiation.
What characterizes chronic leukemia?
A disorder of accumulation where neoplastic cells fail to die, leading to high numbers in peripheral blood.
What characterizes acute leukemia?
A disorder of proliferation where neoplastic cells have a growth advantage over normal cells and fail to differentiate completely.
What are the common clinical signs of chronic lymphocytic leukemia (CLL) in horses?
Edema of the ventrum, prepuce, and limbs, inappetence, weight loss, fever, poor body condition, mild colic, diarrhea, and lymph node enlargement.
What diagnostic techniques are used for leukemia?
Immunophenotyping and cytochemistry.
What is the significance of immunophenotyping in leukemia diagnosis?
It determines the cell lineage by identifying specific markers on the cells.
What is the purpose of cytochemistry in leukemia diagnosis?
To detect enzyme activity within cells, useful for diagnosing acute myeloid leukemia.
What is the prevalence of chronic leukemia in horses?
Quite rare, with few reported cases.
What is a hallmark feature of chronic myeloid leukemia in horses?
A marked increase in cell numbers, particularly persistent and unexplained, or evidence of abnormal maturation.
What are the clinical signs of chronic granulocytic leukemia?
Lethargy, fever, inflamed and slow-healing skin wounds, severe anemia, and thrombocytopenia.
What is the typical signalment for horses with chronic lymphocytic leukemia?
Older horses, usually males, with vague and nonspecific clinical signs.
What is the primary method of diagnosing CLL?
Documenting markedly increased numbers of lymphocytes in peripheral blood.
What is the main differential diagnosis for CLL?
A leukemic phase of a small cell lymphoma.
What are the clinical outcomes of horses with CLL treated with corticosteroids?
Euthanasia after several months due to clinical disease progression or complications like laminitis.
What characterizes acute leukemia in horses?
Presence of greater than 20% immature neoplastic cells (blasts) in the bone marrow.
What is the typical age range for horses affected by acute leukemia?
2-11 years old.
What are the common clinical signs of acute leukemia?
Weight loss, inappetence, fever, edema, lymphadenopathy, depression, diarrhea, colic, and epistaxis.