Lymphoproliferative Disorders Flashcards
What is the difference between lymphoproliferative and myeloproliferative disorders?
LYMPHOPROLIFERATIVE = neoplasms of lymphocytes and plasma cells
MYELOPROLIFERATIVE = neoplasms of bone marrow stem cells, neutrophils, monocytes, erythrocytes, eosinophils, and basophils
What is the difference between lymphoma and lymphocytic leukemia?
LYMPHOMA = neoplasm affecting B or T cells confined to solid tissues
LL = neoplastic process of B or T cells involving bone marrow and/or blood
What is multiple myeloma?
specific B cell neoplastic process affecting plasma cell differentiation
How does the cytological presentation of acute lymphocytic leukemia compare to chronic lymphocytic leukemia?
ACUTE = undifferentiated/immature lymphocytes present, most common in cats infected by FeLV or FIV
CHRONIC = normal appearing and mature lymphocytes present
What lab findings is most important for diagnosing lymphoma ane leukemia? What are 3 differential diagnoses?
lymphocytosis
- excitement response
- neoplastic lymphoproliferative disease (lymphocytic leukemia)
- antigen stimulation in canine ehrlichiosis
What is also expected to see on lab results with lymphocytosis from canine ehrlichiosis?
- large granular lymphocytes
- polyclonal gammopathy
What 2 counts point toward leukemia in dogs?
- > 35000/µL**
- > 15000/µL and tick-borne disease negative
What must acute lymphocytic leukemia be differentiated from? How?
stage V lymphoma (leukemia phase)
ALL has rapid progression in dogs of any age, primarily found in the bone marrow (location tends to be more important than morphology)
Acute lymphocytic leukemia:
- nearly all lymphoid cells are large with prominent nucleoli
- platelets are not seen
- normal leukocytes are rare
- ALL primarily involves bone marrow, which is hypercellular and replaced by lymphoblasts
involvement of bone marrow differentiates it from stage V lymphoma
What are 5 clinical presentations of ALL?
- pale MM
- splenomegaly
- hepatomegaly
- lethargy
- weight loss
What is the most important lab finding with ALL? What 4 other findings are common?
lymphocytosis
- anemia
- thrombocytopenia
- neutropenia
- lymphoblasts in blood
How are lymphoblasts differentiated from lymphocyes?
- morphology: more cytoplasm, nucleoli
- immunophenotyping
- cytochemistry will be negative for most stains, but stain positive for non-specific esterase
What is the prognosis of ALL? How do the types of cells affect this?
poor - rapid, progressive clinical course with poor response to therapy
- CD34+ = extremely poor prognosis with a median survival of 16 days
- CD8+ = slightly better, 131-1068 days
- B cells = slightly better, 129-100 days
What are the 2 major differences between chronic lymphocytic leukemia and ALL?
- lymphocytes are small and appear well differentiated
- more common in dogs
What lab finding is most important for diagnosing chronic lymphocytic leukemia? What 3 differential diagnoses must be considered in cats?
lymphocytosis
- excitement response
- neoplastic lymphoproliferative disease (lymphocytic leukemia)
- antigen stimulation (Bartonella henselae)
What is a common cause of antigen stimulation causing lymphocytosis in dogs? How does it look on cytology?
Ehrlichia canis
large, granular lymphocytes, with a count rarely >10000/µL
What 6 clinical signs are seen in CLL?
- lethargy
- anorexia
- pale MM
- lymphadenopathy
- splenomegaly
- hepatomegaly
- similar to ALL
- tend to be asymptomatic
What lab finding is most commonly seen with CLL? What 4 other findings may be seen? What is commonly seen in cats?
lymphocytosis
- anemia
- thrombocytopenia
- increased small lymphocytes in bone marrow
- monoclonal gammopathy
FeLV negative
CLL:
- arrowheads = small neoplastic lymphocytes
- arrow = large lymphocytes
How are lymphocytes immunophenotyped by flow cytometry?
based on the proteins expressed on their surface
- T-cells = CD3, CD4, CD5, CD8
- B-cells = CD21, CD45, CD11