CS - Lymphadenomegaly case Flashcards
2 main differentials for generalised lymphadenopathy
- neoplasia
- systemic infection
Ddx - noisy breathing
o URT infection
o FB
o Compression of trachea – neoplasm, inflammation, enlarged tonsils
What is the commonest cause of generalised lymphadenopathy in older dogs?
lymphoma
Fastest way to r/o lymphoma
LN FNA (not largest LN or submandibular LN)
How do you differentiate lymphoma from leukaemia?
Flow cytometry (also to type the lymphoma):
- CD45 and CD79a positive = BC lymphoma
- CD34 (stem cell marker) positive = leukaemia
What is a good AB for a dog with lymphoma + neutropaenia?
- bright and afebrile at home: oral ABs e.g. TMS
- sick/ febrile/ GIT signs: IV BS AB e.g. potentiated amoxicillin + enrofloxacin
Is it good to give a blood transfusion for thrombocytopaenia?
No - PLTs have short half-life and there are v few platelets in a unit of blood
Tx - thrombocytopaenia d/t lymphoma
- VINCRISTINE: minimally myelosuppressive, used in IMTP tx, causes megakaryocytes to break off into PLT
- l-asparaginase + prednisolone: not myelosuppressive, helps with thromboctyopaenia and neutropaenia
Chemo protocol - lymphoma + thrombocytopaenia + neutropaenia
- initially start with l-asaparaginase + prednisolone. Otherwise vincristine if owners can’t afford former.
- aim to progress to COP or CHOP protocol (if marked neutropaenia, reduce dose by 20-25%)
Prognosis - lymphoma
- stage 1 and 2 better than stage 5 (not all studies)
- substage b worse prognosis than a
- BC type better than TC for high grade lymphomas
- hypercalcaemia is a poor prognostic indicator
- MST 12-13 months with CHOP
Prognosis ALL on chemo
only 1/3 respond to tx and of those that respond, MST is around 4 months
Does lymphoma or leukaemia show a less prominent lymphadenomegaly in dogs?
Leukaemia
T/F:CS in dogs/cats with lymphadenopathy or splenomegaly are vague and non-specific and usually relate to primary disease rather than the organ enlargement.
True
4 categories - splenomegaly
- lymphoreticular hyperplasia
- inflammatory (splenitis)
- infiltration with abnormal cells (lymhoma) or substances (amyloidosis)
- congestion
If you detect hypoproteinaemia on biochemistry, what might be your next step?
Run serum protein electrophoresis to detect what types of prtoeins were high/low to indicate infection/inflammation or neoplasia
What is the classic serum protein electrophoresis result for dogs with leishmania?
Polyclonal hyperglobulinaemia = high gamma globulins (defined as wide because it was 2-3x the width of the albumin spike, therfore polyclonal, not neoplasia (monoclonal expansion)
What tests are done for leishmania?
- PCR (endemic areas)
- Ab titre (non-endemic areas)
How quickly do dogs seroconvert with leishmania?
- takes up to 24 months, median 5 months
- long incubation period thus most sick dogs are likely to be Ab positive.
Outline PCR in detection of leishmania
- sensitivity BM and LN > skin > conjunctival swab> buffy coat > whole blood
- qPCR most sensitive: sometimes only 30-40% dogs positive with this develop CS
Tx - leishmania
- nothing cures it, only suppresses disaese
- meglumine antimoniate (leishmanicidal) + allopurinol (leishmanistatic) best combination
- alteratively amphotericin B (an antifungal)
- other drugs available if poor response seen
Supportive tx of leishmania with marked proteinuria
- combined meglumine antimoniate + allopurinol –> faster reduction of parasite load –> fewer immune complexes deposited in glomeruli
- low protein, low phosphorous diet
- omega-3 essential fatty acids
- anti-hypertensive therapy
- active vitamin D supplement
- ranitidine
- eryhtropoeitin supplement
Why do you get lymphadenomegaly with leishmania?
d/t increased # and size of lymphoid follicles and marked hypertrophy and hyperplasia of the medullary macrophages in the cords and sinuses.
Why do you get splenomegaly with leishmania?
increased monocyte and macrophage cellularity and changes in the microvasculature structure with abundant pulp venules and veins and increased reticular fibres.
T/F: kidneys are affected in almost all dogs with CanL
True
Why do you get anaemia with leishmania?
• Anaemia present in most symptomatic cases because chronic renal disease or decreased erythropoiesis d/t chronic disease.
Why do you get epistaxis with leishmania?
d/t (insoluble) immune complexes that form. They also develop a rhinitis. The 2 factors combined mean the nosebleed persists.
Ddx - hypercalcaemia
Neoplasia (lymphosarcoma) - commonest Hypoadrenocorticism Primary hyperparathyroidism Chronic renal failure Others ( remember "HARD IONS" for hyperparathyroidism, Addison's disease / hypoadrenocorticism, renal disease, vitaminD toxicosis / dehydration, idiopathic, osteolytic, Neoplastic, spurious - lipaemia or HAEMOLYSIS)
Why are hypercalcaemic animals PU/PD?
- impairs ability to concentrate urine by interfering with ADH at kidney tubules
- acts directly on the thirst centre
Tx - anal sac adenocarcinoma + hypercalcaemia
- deal with hyercalcaemia first, give IVFT, possibly furosemide once hydrated
- advanced LN imaging to ID which are involved and if sx is feasible
- sx for mass and LNs
- chemo for incompletely resected or metastatic cases (various drugs, include carboplatin, melphalan, mitoxaantrone, metronomic or toceranib)
- combination sx, radioation, chemo
- bisphosphonates (pamidronate) if hypercalcaemia remains uncontrolled post-sx
T/F: anal adenocarcinoma tends to metastasise readily to local LNs but can be slow to metastasise further
Ture
Causes - generalised or localised lymphadenopathy
- GENERALISED: metastatic neoplasia, systemic infxn,
- LOCALISED: localised inflammatory or infectious process, metastatic neoplasia
Investigation process - generalised lymphadenopathy
- haematology
- LN biopsy
Investigation process - localised lymphadenopathy
- Think about the specific area that the LN is draining as they are important sites for metastases.
- +/- CBC (less important than generalised lymphadenopathy)
