Leukaemia and lymphadenopathy 3 Flashcards
List the side effects caused by all drugs in chemotherapy for lymphoma
- Nausea, vomiting, diarrhoea
- Hair loss
- Must drugs will cause neutropaenia
Which side effects are owners most likely to be aware of and worried about with chemotherapy?
The signs caused by glucocorticoids i.e. PUPD, hunger, muscle wastage
Outline the treatment for cutaneous lymphoma
- Median survival time only months
- Lomustine and pred used, also CHOP, in some cases retinoids
- Surgery if solitary/localised
- Surgery/radiotherapy for localised epitheliotropic lymphoma of lips/mouth
- Radiotherapy as are easily accessible
What type of treatment is indicated for well/intermediately differentiated MCTs (Grade I, II) with no evidence of metastasis?
Surgical excision
What type of treatment is indicated for well/intermediately differentiated MCT (Grade I, II), with no evidence of metastasis on distal extremities
- If surgery feasible: debulking surgery +/- radiotherapy
- If not feasible: cytoreduction with pre or vinblastine + pred, +/- debulking surgery prior to radiotherapy (oncologist sees tumour before treatment), or Mastinib, toceranib
What type of treatment is indicated for metastatic of poorly differentiated MCTs (Grade III)?
- Surgery if small and no metastasis - risky and not recommended
- Radiotherapy
- Chemotherapy: vinblastine + pred or CCNU
- Grade III: mastinib, toceranib
Outline the treamtnet options for a Grade II MCT that is too big to resect
- Cytoreductive steroids and surgery
- Refer for surgery
- Debulk then irradiate
- Debulk then monitor
- Debulk then chemotherapy
- Tyrosine kinase drugs
Describe the required margins and depth of resection for a Grade I (low grade) mast cell tumour (or grade I soft tissue sarcoma, or well-differentiated dermal squamous cell carcinoma)
- 1cm (wide local) margins
- Down to and including muscle or fascial plane below tumour
Describe the required margins and depth of resection for a Grade II (intermediate grade) mast cell tumour (or poorly differentiated dermal squamous cell carcinoma)
- 2cm margins (wide local)
- Down to and including muscle or fascial plane below tumour
Describe the required margins and depth of resection for a Grade III (high grade) mast cell tumour (grade II and III soft tissue sarcomas (spindle cell sarcomas), feline vaccine associated sarcomas)
- 3cm margins (radical)
- Down to and including 2 muscle or fascial planes below tumour
Name tyrosine kinase inhibitors used in the treatment of lymphoma
Masitinib, toceranib
Discuss the use of tyrosine kinase inhibitors in the treatment of mast cell tumours
- Proliferation/survival of mast cells controlled by c-kit receptor tyrosine kinase
- If use TKIs, life long therapy, will not get rid of tumour
- Expensive
- Can cause many side effects
- Relatively high morbidity
- Can work well, but need close monitoring
Describe the side effects caused by masitinib and toceranib
- Masivet: protein losing nephropathy
- Palladia: neutropaenia, muscle cramps
- Both: anorexia, vomiting, bleeding, can induce thrombocytopaenia
When should lymphoma or mast cell tumour cases be referred?
- If advanced skin reconstruction required
- For radiotherapy
- For chemotherapy if unsure of drugs and protocols, side effects and protection of people
- For incompletely excised tumours
Describe the treatment options for feline mast cell tumours
- Excise cutaneous and splenic ones
- Radiotherapy possible but often diffuse or benign so questionable value (surgery better)
- Little published data on chemo
- Corticosteroids unclear benefit in cats
- TK inhibitors have had preliminary investigations in cats
Discuss the use of chemotherapy in the treatment of feline mast cell tumours
- Chemo generally reserved for cats with histologically pleomorphic (diffuse) locally invasive and/or metastatic tumours
- Vinblastine, chlorambucil, lomustine used
Compare the response to treatment of acute and chronic leukaemia
- Acute (poorly differentiated) poor response to treatment
- Chronic (well differentiated) reasonable response to treatment
Outline the pathogenesis of multiple myelomas (plasma cell)
- Secrete excess Igs of one clonal class
- Usually present due to paraneoplastic signs associated with hyperviscosity
Describe the clinical presentation of lymphoid leukaemia in dogs
- Usually middle aged to older
- Non-specific clinical signs incl: lethargy, weight loss, PUPD, anorexia
- Anaemia and thrombocytopaenia
- High numbers of white cells on smear usually, but may have aleukaemic presentation with no peripheral blood component
Describe the acute lymphoblastic form of lymphoid leukaemia in dogs
- Very acute
- More common than chronic forms
- Live max. 30 days, but usually only a couple of weeks
What is commonly found in cats with acute lymphoid leukaemia?
FeLV positive
How is lymphoid leukaemia diagnosed?
- Blasts in acute, mature lymphocytes in chronic on blood smears
- Some acute are aleukaemic
- May have Bence Jones proteinuria
- Cell markers can be prognostic so flow cytometry can be useful
Outline the treatment of chronic lymphoid leukaemia
- Only if chronically ill
- Prednisolone and chlorambucil
What is polycythaemia vera?
Chronic red blood cell leukaemia, more common in dogs than cats and is the most common myeloproliferative disease
Describe the presentation polycythaemia vera
- Chronic non-aggressive
- Present with bone marrow derived polycythaemia, very high PCV
- May struggle to get blood through needle due to viscosity
Describe the treatment of polycythaemia vera
- Phlebotomy
- Hydroxurea (may lead to nail sloughing, otherwise well tolerated), most common drug
- Iron supplementation
- Leaches
Describe multiple myelomas
- Clonal proliferation of plasma cells in marrow
- Excessive Ig, M component, may be light chain only (Bence Jones protein)
Describe the presentation of multiple myelomas in horses
May become hypercalcaemic and have elevated parathyroid hormone-related protein (PTHrP), and hyperglobulinaemia
Describe the presentation of multiple myelomas in cattle
- Nosebleeds
- Emaciation
- Hyperglobulinaemia
- Amyloid deposition in lymph nodes, kidney, spleen, liver
- Enlarged lymph nodes
Describe the presentation of multiple myelomas in dogs and cats
- More common in dogs than cats
- Hyperviscosity (bleeding, renal disease)
- Hypercalcaemia of malignancy
- Cytopaenias; anaemia, thormbocytopaenia, neutropaenia
- Severe bone pain: multiple lucencies (shot gun lesions), fractures, bone marrow affected
How is multiple myeloma diagnosed?
- Bone marrow aspirate
- Urinary Bence Jones proteins
- Serum protein electrophoresis (look for clonal Igs from one plasma cell clone population)
Outline the treatment and prognosis of multiple myelomas
- Pred and melphalan, plasmapharesis
- May do well with treatment
- Median survival time in dogs up to 18 months
Outline the behaviour of extramedullary plasmacytomas
- Varies with anatomical location
- Oral cavity and cutaneous usually benign
- Intestinal usually malignant, but colonic more favourable prognosis
Outline the clinical signs of extramedullary plasmacytoma
Relate to location and presence of paraneoplastic conditions
Outline the management of extramedullary plasmacytomas
- For solitary disease: surgery and monitoring, oral and cutaneous can be curative
- For alimentary: surgery followed by chemo when spread documented, recurrence common and metastasis ~1yr or more can be seen
Name the disease of importance regarding the thymus of birds
Chicken infectious anaemia (chick anaemia virus, Circovirus)
List the diseases of importance regarding the Bursa of Fabricius
- Infectious bursal disease (Birna virus, Gumboro disease)
- Tumours
List the diseases of importance regarding the spleen of birds
- Tumours: Mareks disease (herpesvirus), Avian leukosis (retrovirus), reticuloendotheliosis (adenovirus)
- Marble spleen disease of pheasants (adenovirus)
- Haemorrhagic enteritis of Turkeys (adenovirus)
Explain why chicks are most susceptible to infectious bursal disease
- Disease requires presence of functioning bursa
- Young chicks 3-8wo most susceptible
- Atrophies with age
Describe the aetiology of Infectious Bursal Disease
- Birna virus trophic for B lymphocytes
- Very resistant virus that persists in environment and difficult to eliminate from flock
Describe the clinical signs of Infectious Bursal Disease
- Depression, ataxia, ruffled feathers (head and neck)
- Diarrhoea (stained around vent)
- Anorexia
- Acute mortality
- Varible long term immunsuppression +/- secondary infection in chronic state
Describe the gross lesions found in Infectious Bursal Disease
- Bursa enlarged, oedematous, congested, +/- haemorrhagic
- Muscular haemorrhages
- +/- swollen kidneys
Describe the control of Infectious Bursal Disease
- Cleaning and disinfection of housing
- Vaccination complicated
- In broilers: 1 live vaccine at 4 weeks, 1 inactivated at 16 weeks to protect progeny
- Egg layers: 1 live vaccine around 4 weeks
Describe the “gold standard” vaccination protocol for Infectious Bursal disease
Obtain blood samples from day old chicks for serology to decide age and vaccine that should be used
Describe the aetiology and epidemiology of Mareks disease
- Common presentation of backyard chickens
- Most common in 2-7mo chickens, also turkey, pheasant, quail
- Herpesvirus (gallid herpesvirus 2), chronically infected
Describe the pathogenesis and transmission of Mareks disease
- Initial viral replication in lungs
- Cytolytic phase in lymphocytes: immunosuppression
- Latent phase: transformation and lymphomas
- Virus shedding from feather follicle epithelium
- Incubation period: 4 weeks min, usually longer
- Asymptomatic shedding possible
- Infected birds viraemic for life
Describe the clinical signs of Mareks disease
- Depression, cachexia
- Presented dead most common
- Blindness
- Secondary infection/ill thrift
Describe the gross lesions seen with Mareks disease
- Tumours - all parenchymatous organs common
- Swollen nerves
- Swollen feather follicles (lymphocytic folliculitis)
- Iris infiltration (less common)
- Swollen nerves and iris infiltration are pathognomic
Describe the histopathological lesions seen with Mareks disease
- T cell lymphosarcoma
- Lymphocytic neuritis
- Perivascular cuffing in brain
Outline the treatment and control of Mareks disease
- No treatment
- Hygiene and disinfection
- Backyard: Ensure vaccination of new stock (in ovo or as day old chicks)
- Commercial: long lived birds all vaccinated
- Several serotypes of vaccine available, all require injection, goo technique important for protection
- Destocking
Describe canine thymoma
- Rare tumour of thymic epithelium
- Usually self contained, some may spread
- Usually cranial mediastinum
- Not usually associated with distant spread
Describe the clinical signs of canine thymoma
- Respiratory distress
- May see cranial caval syndrome (swollen head)
- Myasthenia gravis
Explain how canine thymomas cause cranial caval syndrome
Impaired drainage
Explain how canine thymomas cause myasthenia gravis
- Paraneoplastic
- Antigen mimicry from thymoma
Describe the diagnosis of canine thymoma
- Large thoracic mass on radiology (tracheal displacement and cranial focal soft tissue opacity)
- Biopsy to distinguish from lymphoma
- Flow cytometry
- FNA will showa non-clonal population of lymphocytes
Outline the treatment and prognosis for canine thymoma
- Surgery to remove if possible, refer
- Prognosis good if resectable
- May involve major vessels and nerves so cannot be resected
Describe the identification and possible causes of disease of the spleen in cattle
- Most found at PM
- key differential for splenomegaly: anthrax
- Tyre-wire/hardwire possible abscess
Describe the diseases of the spleen in pigs
- Rarely the only organ involved
- Splenic infarcts in swine fever
- Splenomegaly: PMWS circovirus) and Glasser’s disease (Haemophilus parasuis)
- Erysipelas: moderate to marked splenomegaly
Describe the diseases of the spleen in horses
- Well anatomically protected
- Can be involved in colic (nephrosplenic entrapment)
- Other diseases very rare
- Can be removed if needed
Describe the diseases of the spleen in alpacas
Splenic haematomas and torsions seen
Describe the diseases of the spleen in cats
- Splenic haemangiosarcoma rare
- Splenic MCT more common: mean age ~10yo, splenomegally +/- effusion
Describe the diseases of the spleen in dogs
- Splenic masses moderately common
- Haematoma>neoplasia
- Common site for metastasis
- Present as mass or haemabdomen
- Often incidentally found at vaccine/general exam
- Can present with circulatory collapse
- Haemangiosarcoma 36%, 60% benign masses e.g. haematoma, 4% other malignancies
Describe the presentation of splenic disease in dogs
- Mid abdominal mass usually ventral, non-painful
- May have widespread mets if HSA so +/- cough
- Splenic torsion as part of GDV
Describe the presentation of a ruptured splenic mass in dogs
- Pallor
- Tachypnoea, tachycardia
- Ascitic/distended abdomen
- may have palpable fluid thrill
- SUdden death feasible if huge bleed
- Waxing and waning signs over moths with repeated bleeding and recovery
List the diagnostics included in the investigation of splenic disease in the dog
- Haematology to check PCV
- Palpation
- Imaging (radiography + ultrasound)
- Abdominocentesis if free fluid seen
- FNA/biopsy mass/splenectomy
Discuss the approach to surgery for the treatment of splenic disease in dogs
- Hard to get good diagnosis pre-op
- Met check thorax
- Care re. coagulopathy
- Replace blood volume pre-op
- Splenectomy better than hemi
- Care with post-op arrhythmias, monitor 24-48hrs post op
Outline the treatment approach to haemangiosarcomas that have metastasised to the spleen
- Commonly in lungs, liver, LNs, brain and potentially skin/SC tissues
- Surgery primary treatment (check abdo for mets)
- Post op chemotherapy indicated in almost all cases
Discuss the prognosis for splenic haemangiosarcomas
- Splenectomy alone: survival 3 months
- Splenectomy + chemotheraoy: 6 months
- Die of diffuse metastatic disease, better prognosis if no splenic rupture
- Doxorubicin every 3 weeks
List the differential diagnoses for a group of calves showing sudden onset bleeding and petechiation
- Anthrax
- Rat bait poisoning
- Bracken fern toxicity
- Bovine neonatal pancytopaenia
- BVDV
- Trichothecene mycotoxicosis
- Sepsis
- Electrocution
- Primary haemostatic disorders
List the differential diagnoses for a group of calves showing sudden onset lethargy/recumbency and death
- IBR
- Anthrax
- Clostridial disease
- Hypoglycaemia
- Nutritional deficiency
List the differential diagnoses for a group of calves showing submandibular swellgin
- Blocked salivary galnd
- Enlarged submandibular lymph node
- Haematomas
- Infection (lumpy jaw/wooden tongue/calf diptheria), abscess
- Oedema (cardiovasular origin)
- Submandibular hypoplasia
List the differentials for primary haemostasis disorders in cattle
- Acute bracken fern toxicity
- BVDV
- Trichothecene mycotoxicosis
- Bovine neonatal pancytopaenia
- Ingestion of other bone marrow suppressive substances e.g. furazolidine nitrofuran antibiotic
- Platelet malfunction e.g. inherited bovine thrombopathia in Simmental cattle
Describe acute bracken fern toxicity in cattle
- Usually young stock affected
- Pyrexia, bloody diarrhoea, epistaxis, bleeding from eyes or vagina
- Haematuria and petechial haemorrhages
- death usually 1-3 days after onset of signs due to bacteraemia and massive haemorrhage into GIT
List the differentials for secondary haemostasis disorders in cattle
- Inherited deficiency of coagulation factors
- Acquired deficiency of coagulation factors
- Disseminated intravascular coagulation
In a group of calves showing sudden onset petechiation and lethargy, what do the following haematological findings indicate?
Non-regenerative normochromic normocytic anaemia, thrombocytopaenia, neutropaenia, leukopaenia, lymphopaenia
All indicate bone marrow destruction, suggestive of bovine neonatal pancytopaenia
List your differentials for a bilateral submandibular, non-painful swelling
- Infection
- Neoplasia
- Non-infectious inflammation
- Sialocoele
List your differentials for PUPD
- Renal disease
- Endocrinopathy
- Cystitis
- Neurogenic/psychogenic polydipsia
- Hypercalcaemia (neoplasia)
