Oncology: Canine Lymphoma

Question 1

What do lymphomas arise from?

Answer 1

Lymphoreticular
T or B cells

normally from lymphoid tissue

Question 2

What aetiology increases lymphomas?

Answer 2

Multifactoral and largely unkoen

• Genetic and molecular factors
• Infectious disease
• Toxins
• Immunologic factors

Question 3

What are the different anatomical classifications of lymphomas?

Answer 3

Most common to least common
* Multicentric
* Craniomediastinal
* Gastro-intestinal
* Cutaneous
* Extra-nodal forms

Question 4

How do multicentric lymphomas present?

Answer 4

Generalised peripheral lymphadenopathy
* Moderate to marked lymph node enlargment
* Regional oedema- if lymph drainage impaired
* Non-specific signs

Question 5

What do these images show?

Answer 5

GI (alimentary) lymphoma

Vomiting, diarrhoea, weight loss, pan-hypoproteinaemia

Abdominal mass or diffuse

Tends to be aggressive in dogs

Question 6

What are the different froms of cutaneous lymphoma?

Answer 6

Epitheliotropic
* T cell
* Solitary or generalized

Non-epitheliotropic
* B cells
* Lesions else where likely

Question 7

Where can extranodal lymphoma form?

Answer 7

Hepatosplenic
* Aggressive- T cell

CNS
Renal
Urinary bladder
Heart

Question 8

What is paraneoplastic syndrome?

Answer 8

Syndrome that is a consequence of the tumour
* Hypercalcaemia
* Immune mediated diseases (IMHA)
* Monoclonal gammopathies
* Neuropathies
* Cachexia- muscle loss

Question 9

What is the differential diagnosis of multicentric lymphoma?

Answer 9

Infectious disease

Question 10

How is lymphoma diagnosed?

Answer 10

Cytological or histopathological

Ancillary tests: PARR, flow cytometry, immunochemistry

Question 11

What is stage I-V lymphoma

Answer 11

• I- involvement limited to a single lymph node
• II-Involvment of lymph nodes in a regional area ± tonsils
• III- Generalised lymph node involvement
• IV- Hepatic and/or splenic involvment
• V- manifestations in the blood and involvement of bone marrow

Question 12

How is lymphoma staged?

Answer 12

• Haematology
• Biochemistry- hypercalcaemia
• Aspirate or biopsy of other lymph nodes
• Thoracic radiographs, abdominal US
• Bone marrow biopsy

Question 13

How can lymphoma be treated?

Answer 13

• No treatment- asymptomatic MST 4-5 weeks

Prednisolone alone
* Objective response rate 30% for 1-2 months

Multidrug chemotherapy
Survival depends on protocol and individual response

Question 14

What are the different protocols for multidrug chemotherapy for lymphoma?

Answer 14

High dose COP
* preferred to low dose
* well tolerated
* haematology prior to each treatment
* Urine sample before cyclophosphamide
* response rate 60-80&
* MST 6-9 months

Discontinuous CHOP/CEOP
* Response rate 90-95%
* MST 10-12 months
* No advantage to continuous treatment

Question 15

What are the potential side effects of chemotherapy?

Answer 15

• GI toxicity
• Myelosupression- neutropenia, thrombocytopenia, anaemia

Drug specific toxicities
* Sterile haemorrhagic cystitis: cyclophosphamide
* Cardiotoxicty: Doxorubicin/Epirubicin
* Lomustine: Hepatotoxicity- monitoring of ALT and liver protectors

Question 16

When might radiation or surgery be indicated?

Answer 16

Radiation
* Stage I disease
* Palliation of local disease
* Mass lesion on CNS

Surgery
* Could be considered for rare Hodgkins lymphoma

Question 17

How is epitheliotropic lymphoma treated?

Answer 17

COP or lomustine/prednisolone

Radiation therapy is very useful for localised mucocutaneous disease

Question 18

How can prognosis be decided?

Answer 18

Assess response
* Palpation of lymph nodes
* Resolution of clinical signs
* Repeating imaging
* Monitoring blood parameters

Question 19

What rescue protocols can be used for canine lymphoma?

Answer 19

DMAC- dexamethasone, melphalan, Actinomycin-D, Citarabine

LPP- Lomustine, procarbazina, prednisolone

After dog stops remission- to return back to remission