CO5 slides Flashcards
primary sites for lymphoma in the dog
- Primary ocular, nervous system, gastrointestinal, renal, etc. lymphoma.
blood picture of canine lymphoma
- Blood picture: most dogs do not have a lymphocytosis, but have normal or even decreased lymphocyte counts.
- Mild anemia in 20-50% of dogs with lymphoma
- Bone marrow involvement is typically absent or
inconspicious
cats - nodal or extranodal lymphoma? location and age?
- More frequently extranodal than nodal
- Most common solitary intestinal mass in older cats
- Other common sites are kidney, liver, mesentery, CNS
cat lymphoma cell type
- T (common) or B (uncommon) among intestinal lymphoma
what lymhomas in cats are almost always T cell type? associated with what imbalance?
- Mediastinal lymphomas almost always T cell type, common in FeLV infected cats, and associated with hypercalcemia
is it common for FeLV infectino to cause lymphoma? how could this happen?
- FeLV is a retrovirus that makes a DNA copy of its RNA genome, and inserts this copy into the host cell genome
- During this process is may “pick up” or activate cellular proto-oncogenes, and their gene product may then be over expressed
- Relatively uncommon event during FeLV infection i.e. most FeLV-infected cats don’t get lymphoma
- FeLV infection is less common in recent years
- Only mediastinal lymphoma is relatively common among FeLV-infected young cats
FIV and lymhoma - how can it cause it? what type?
- FIV is also retrovirus
- Causes slowly progressive disease
- Clinical illness several years after infection
- Loss of CD4+ helper cells
- Opportunistic infections, stomatitis, diarrhea, etc.
- Aggressive extranodal lymphomas are common among FIV- infected cats
- No virus in tumor cells = indirect effect
- Due to chronic immune stimulation, lack of immunosurveillance, proliferation of other viral agents?
lymphoma in horse - how common? what cell type? associated with what? what nodes?
- Cancer is uncommon in horses, but lymphoma is among the most common cancers
- T-cell lymphomas more common than B-cell lymphomas
- Often associated with inflammation (histiocytes, plasma cells,
necrosis) and anemia - Peripheral lymph nodes rarely involved
Cutaneous lymphoma in horses - what age group, how do they change over time?
older horses, may wax and wane in response to estrogen or progesterone
Mesenteric or intestinal lymphoma in horses associated with what condition
often associated with immune hemolytic anemia
mediastinal lymphoma in horse is what cell origin?
- Mediastinal lymphoma = T cell origin
what species is more likley to get gammopathy with lymphoma than other species?
horse
most cattle with BLV get what condition?
Most infected cattle get persistent lymphocytosis, but not
lymphoma
* 2 to 4% of BLV infected cattle proceed to develop lymphoma
Classification of lymphoma
- Histopathology classification – architecture of lymph node and morphology of tumor cells:
Diffuse vs nodular; high, medium, or low grade - Immunophenotype – CD expression of tumor cells:
Good prognostic information in dogs but less so in other species - Cytogenetics, molecular genetics – starting, don’t know yet how genetic changes relate to prognosis
Cytology of splenic aspirates
- extramedulary hematopiesis finding?
- spindle cells?
Extramedullary hematopoiesis = normal finding in almost all cases
A couple of spindle-shaped cells = could be hemangiosarcoma but need architecture (histopathology) for confident diagnosis
