Feline lymphoma, leukaemia and myeloma Flashcards
Pre-FeLV lymphoma is most commonly in which form?
Mediastinal/multicentric lymphoma in young/adult cats
Post-FeLV lymphoma is most commonly in which form?
Gastrointestinal lymphoma in geriatric cats
What is the most common form of feline lymphoma?
Gastrointestinal lymphoma in geriatric cats
How is FeLV linked to lymphoma?
One of the most important aetiologic factors
FeLV+ have 62 times risk of developing lymphoma
Are feline lymphomas more commonly T or B cell?
B-cell
List some other aetiological factors for feline lymphomas
- Genetic predisposition
- Altered expression of oncogenes, tumour suppressor genes
- Epigenetic modifications
- Tobacco smoke
- Chronic inflammatory conditions (i.e. IBD)
List the different types of lymphoma cats can get
Nodal lymphoma (multicentric)
Alimentary lymphoma
Mediastinal lymphoma
Extranodal lymphoma
- Nasal/retrobulbar lymphoma
- Laryngeal lymphoma (pharynx and trachea)
- Renal lymphoma
- CNS lymphoma
- Ocular lymphoma
- Cutaneous lymphoma
Describe ‘true’ multicentric lymphoma in cats
“True” multicentric lymphoma with symmetrical generalised lymphadenopathy is rare in cats (most common form in dogs)
List the clinical signs of nodal/multicentric lymphoma in cats
Non-painful lymph node enlargement
Anorexia
Depression
Non-specific malaise
Pyrexia
(PU/PD)
What are some DDx of nodal/multicentric lymphoma in cats
- Retroviral, viral, bacterial, fungal, mycobacterial and (protozoal), infections
- (Other haemopoietic malignancies)
- Immune mediated disease
- Idiopathic forms
- Metastatic disease (regional)
Mediastinal lymphoma is most commonly seen in which cats?
Younger cats? - Siamese?
List the clinical signs of mediastinal feline lymphoma
Respiratory distress
Regurgitation/dysphagia
Weight loss
Lethargy, exercise intolerance
Cough (rare)
On clinical exam what findings may indicate a mediastinal lymphoma?
Palpable reduction in compressibility of cranial thorax
Decreased lung sounds
List the DDx for mediastinal feline lymphoma
Thymoma (double pos CD4/CD8)
Other cranial mediastinal lymphadenopathy
Other causes of pleural effusion
- Congestive cardiac failure
- Pyothorax
- FIP
- (Haemothorax)
Describe the clinical presentation/signs of a cat with alimentary lymphoma
- Older cats
- Insidious weight loss
- Anorexia: more common and severe in cats than dogs
- Diarrhoea (may not be observed)
- Malabsorption/PLE
- Occasionally vomiting
List the DDx of feline alimentary lymphoma
- Many and various other causes of GI signs
- All other causes of mesenteric lymphadenopathy: FIP, IBD, metastatic neoplasia, pancreatitis, mycobacterial infection
List the clinical signs of a nasal/retrobulbar extranodal lymphoma
Nasal discharge, epistaxis, obstruction, exophthalmos etc.
List the clinical signs of a renal extranodal lymphoma
Malaise, anorexia
Renomegaly (bilateral)
Azotaemia
Describe the main features of renal lymphoma
- Degree of azotaemia is not prognostic of outcome
- Overall low response rate and poor survival time
- High incidence of CNS involvement in cats with renal lymphoma
Which form of cutaneous lymphoma is most commonly seen in cats?
Non-epitheliotropic
Describe the use of FNA is feline lymphomas
Cats often have low grade small cell or mixed lymphomas
- Especially multicentric/peripheral lymphomas
- Difficult to differentiate from reactive hyperplasia on cytology
- FNAs are much less likely to be diagnostic than in dogs
Which forms of feline lymphoma may be easier to diagnose on FNA, why?
Cranial mediastinal and extranodal lymphomas may be higher grade - Easier to diagnose on FNA
Describe the use of biopsy for feline lymphomas
- Excisional biopsy of node
- Avoid Trucut needle biopsies: except for renal lymphoma (check co-ag times)
- Wedge biopsy from extranodal lesion or enormous node
- Impression smears
What does PARR stand for?
PCR for antigen receptor rearrangements
Describe the pros of using PARR for diagnosing lymphoma
- Clonality is a feature of neoplasia
- Identify a clonal population in a background of normal lymphocytes
- High specificity, a positive results support the diagnosis of lymphoma
Describe the cons of using PARR for diagnosing lymphoma
- Clonality is not only a feature of neoplasia
- Oligoclonality and monoclonality in inflammation
- Negative result if no enough cells
- Primers
- Identify only 65-70% of lymphomas in cats
- A negative result does not exclude lymphoma
Compare staging of tumours in cats compared to dogs
- Cats do not fit in the standard clinical staging ‘boxes’ used for dogs
- Numerous staging systems allowing for anatomical site proposed
What are the positive prognostic indicators for feline lymphoma?
- Achieving a complete response
- Small volume of extranodal disease
What are the negative prognostic indicators for feline lymphoma?
- Failure to achieve a complete response
- FeLV +ve status
- Previous therapy with corticosteroids
List the treatment options for feline lymphoma
(None)
Corticosteroids
Multi drug regimens
- COP
- CHOP
- COAP
Which multidrug regime is most used in cats with lymphoma?
COP is an excellent protocol for cats
- High dose COP
- 1 year survival 49%, 2 year survival 40%
- Vincristine, cyclophosphamide, prednisolone
How should patients be monitored for side effects following chemotherapy?
Myelosuppressive agents
- Check haem prior to every bolus dose
- On low dose COP, check at appropriate intervals
Probably a good idea to intermittently check urine
- ?UTI
Hair loss (whiskers)
GI signs
Describe how to treat alimentary lymphoma in cats
- Surgical excision of solitary mass lesion: Must biopsy nodes (and other organs)
- Follow up chemotherapy (?)
- Adequate supportive therapy: Appetite stimulants, O-tube? Vitamin B12
- Gastric lymphoma very difficult to treat
How is leukaemia classified?
Classification by cell type and progression
- Acute vs chronic
- Lymphoid vs myeloid
Describe the prognosis of leukaemia
Acute lymphoid leukaemia (ALL) and acute myeloid leukaemia (AML) are rapidly progressive, fatal diseases
- High WBC counts
- Concurrent pancytopenias
- Poor prognosis (weeks-months) even with chemotherapy
Which syndromes is recognised as a precursor to acute leukaemias in FeLV positive cats?
Myelodysplastic syndrome (MDS)
How is Myelodysplastic syndrome (MDS) characterised?
Cytopenias (RBCs, platelets, neutrophils) without circulating neoplastic cells.
Describe treatment for acute leukaemia’s
Supportive therapy – very sick patients
- Blood transfusion
- Antibiotics
- Barrier nursing
- CSF?
Multi-agent chemotherapy protocols
- COP vs CHOP
- Addition of cytarabine infusions may improve response
Define chronic lymphoid leukaemia
Proliferation of mature lymphocytes in bone marrow.
Rare (T cell > B cell > T-ve, B-ve)
Describe treatment of chronic lymphoid leukaemia
Decision to treat based on the individual (presence of CS, degree of lymphocytosis)
Treatment with prednisolone/chlorambucil – survival times of 1-3 years reported.
Define chronic myeloid leukaemia
Proliferation of mature myeloid cells (normally neutrophils) in bone marrow
Even rarer!
When diagnosing chronic myeloid leukaemia, which conditions need to be excluded?
Have to exclude other causes of extreme neutrophilia; infection, immune mediated disease; paraneoplastic syndrome
How is leukaemia diagnosed?
- Haematology with manual differential and smear evaluation
- Flow cytometry of peripheral blood
- Staging to evaluate extent of disease
- Thoracic radiographs
- Abdominal ultrasound
- Cytology of liver/spleen - Bone marrow biopsy (cytology + histology)
Name a myeloid related disorder
Multiple myeloma
What is multiple myeloma?
- Rare - <1% of malignant tumours in animals
- Systemic neoplastic proliferation of plasma cells results in overproduction of antibody (IgA or IgG)
- Can get local disease – extramedullary plasmacytoma which can progress to multiple myeloma
In multiple myeloma, hyperproteinaemia can lead to ..?
Hyperviscosity syndrome
Describe the characteristics of hyperviscosity syndrome
Neurological symptoms, retinal detachment, congestive heart failure (cats > dogs), hypertension, coagulopathy
Describe the haematology, biochemistry and urinalysis characteristics in a patient with multiple myeloma
- Non-specific, may see circulating plasma cells
- Proteinuria (Bence-Jones proteins)
- Hypercalcemia
- Hyperglobulinemia
How else is multiple myeloma diagnosed?
- Serum protein electrophoresis: Monoclonal gammopathy
- Diagnostic imaging: Hepatosplenomegaly, Osteolytic bone lesions
- Cytology: Liver, spleen + bone marrow
In dogs, to confirm diagnosis of multiple myeloma they need to have at least 2/4 of which criteria?
- Monoclonal gammopathy
- Radiographic evidence of osteolytic bone lesions
- > 5% neoplastic plasma cells or >10-20% plasmacytosis in the bone marrow
- Bence-Jones proteinuria
How is multiple myeloma different in cats?
In feline myeloma related disorder there is rarely bone marrow involvement so should demonstrate plasma cell infiltration of visceral organs.
How is multiple myeloma treated?
Supportive care
- Blood transfusions
- Plasmaphoeresis
- Antibiotics if secondary infection
- Therapy for hypercalcaemia
Systemic disease
- Prednisolone (~ 40 days)
- Chemotherapy
