Exam 7 L. 8 Flashcards Preview

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Flashcards in Exam 7 L. 8 Deck (12):
1

Canine lymphoma

1) Proliferation of the malignant population of lymphocytes
2) very common
3) lymphoma is *most chemoresponsive*and will be the neoplasm most frequently treated private practice!

2

Presentation of lymphoma

1) typical clinical presentation-80%
-painless, peripheral lymph node enlargement for a few days to weeks/months
-systemic signs vague or no other signs
2) other locations involved-signs reflect organ system involved
-mediastinal: respiratory signs
-G.I.: anorexia, vomiting, diarrhea, melena

3

PARR (PCR for antigen receptor rearrangements)

1) lymphocytes carry unique DNA sequences
2) as they undergo differentiation there is rearrangement of genes in response to stimuli
3) B cells carry immunoglobulin, T cells carry the T cell receptor
4) neoplastic lymphoid cells DNA rearranged into CLONAL/HOMOGENOUS POPULATION*
5) PARR-monoclonal malignant lymphocytes population with SAME genetic defect
-sensitivity: 1 malignant cell per 100 lymphocytes (85% sensitive that 99% specific for dogs; less sensitive in cats)

4

Flow cytometry

1) flow cytometry is the method of choice for phenotyping
2) correlates with survival time, guides treatment choices
3) CD45 needed for cell apoptosis!

5

WHO clinical staging criteria for canine lymphoma

1) stage I: disease confined to a single lymph node
2) stage II: regional lymphadenopathy (one side of the diaphragm)
3)*stage III*: *generalized lymphadenopathy*(most common!)
4) stage IV: hepatosplenomegaly
5) stage V: bone marrow, CNS, or extranodal site

Substage A: no clinical signs
Substage B: clinical signs of illness

6

Prognostic factors for canine lymphoma

1) prognostic factors influence remission and survival
2) most important is immunophenotype and substage*
3) better prognosis
-initial response to therapy in 4-6 weeks
-immunophenotype (B cell typically better than T cell)
-negative bone marrow, normal liver biochemistry

7

Negative prognostic indicators for canine lymphoma

1) substage b: clinical signs of illness present
2) higher clinical stage (IV, V worse)
3) hypercalcemia
4) location-mediastinal
5) extranodal location: G.I., primary hepatic, skin, CNS
6)**pretreatment with prednisone**(more than 2 weeks)
-selects for resistance to chemotherapy!

8

Feline lymphoma

1) more than 50% tumors cats!
2) cats living with smokers >5 years + have 3x increased risk for G.I. lymphoma and oral cancer!
-Cats get carcinogens on the coat, then they groom themselves

9

Feline lymphoma

1) clinical signs associated with the body system lymphoma is present in
2)*most common form is G.I.*

10

Cats with mediastinal lymphoma

1) 2-3 years old
2) overall response rate to CHOP protocol: 90%
3) MST for entire group 1 year

11

Cats G.I. lymphoma

1) G.I. LYMPHOMA IS THE MOST COMMON FORM

2) may see weight loss, inappetence, vomiting/diarrhea
3) up to 2/3 have palpable abdominal mass, thickened intestines

12

Lymphoma: dogs versus cats

1) clinical signs relate to the organ system involved in both species
2)*MOST COMMON FORM IS PERIPHERAL LYMPHADENOPATHY FOR DOGS AND G.I FOR CATS**
3) most cats are sick at presentation, most dogs are not
4) hypercalcemia is more common in dogs
5) the response to chemotherapy in dogs is better than in cats