Lymphoproliferative Disorders Flashcards
(52 cards)
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
How is immunophenotyping used for prognosis of lymphoma/leukemia?
- CD34 expression predicts POOR outcome
- CD8 with high lymphocytosis has shorter survival time than with normal/decreased lymphocytes
- CD21 B-cells with large lymphocytes survive LESS time than patients with small cells
What 2 trends are seen with canine prognosis of lymphoma/leukemia?
- old dogs with B-cell leukemia survive longer than young dogs
- dogs with T-cell CLL and no anemia survive longer
What is lymphoma?
systemic, diverse, heterogeneous disease that results from the uncontrolled clonal expansion of malignant lymphocytes in solid tissue
What are some ways to classify lymphoma?
- anatomic distribution in body
- histologic distribution in organ
- cytomorphology
- immunophenotyping by flow cytometry, IHC, and PARR to detect B-cells, T-cells, and aberrant cells
- cell size
- grade by mitotic index
- MHC II expression
- stage at presentation
- molecular characteristics
- biological behavior (indolent, aggressive, response to treatment