Lymphoreticular and Haemopoietic Flashcards
What are the primary lymphoid organs?
Bone marrow and thymus
What are the secondary lymphoid organs?
Lymph nodes, spleen and MALT
What are the top DAMNITV differentials for pathology of the lymphoreticular system?
Infection
Immune-mediated
Neoplasia
Name some diseases of the thymus?
Thymic hypoplasia Thymic lymphoma (cats) Thymoma (dogs)
What causes thymic hypoplasia?
Developmental abnormalities- associated with primary immunodeficiency e.g. X linked SCID
Systemic viral lymphoid depletion- FeLV, FIV, CDV
What is associated with feline thymic lymphoma?
FeLV- infects lymphocytes and undergoes malignant transformation
What are the clinical signs of feline thymic lymphoma?
Anorexia, weight loss, dyspnoea
How do you diagnose feline thymic lymphoma?
Thoracic radiography (mass in anterior thorax, effusion) Cytology of pleural fluid/ FNAB
What is the treatment for feline thymic lymphoma?
Chemotherapy
What is canine thymoma?
Neoplasia of thymic epithelial cells. Slow growing and low metastatic potential
Which breeds are overrepresented for canine thymoma?
GSDs and labrador retrievers
What are the clinical signs of canine thymoma?
Dyspnoea, dysphagia, thoracic effusion
How do you diagnose canine thymoma?
Thoracic radiography, ultrasound, cytology of fluid/ FNAB
What is the treatment for canine thymoma?
Surgical excision +/- chemo
What is the prognosis for canine thymoma?
Good if tumour hasn’t spread beyond thymic capsule
What paraneoplastic syndromes are associated with canine thymoma?
Myasthenia gravis
Hypercalcaemia
What is the process of lymphocyte recirculation?
Circulate in blood visiting secondary lymphoid organs via HEVs. If fail to recognise anything return to blood via efferent lymphatic vessels and thoracic duct.
What are the functions of the LNs?
Trap foreign material, optimise exposure of lymphocytes to Ag. Provide best environment for lymphocyte activation, proliferation and differentiation, producing effector T cells and Ab from plasma cells.
How does chylothorax occur?
Where the thoracic duct is damaged/ perforated or eroded by a tumour, efferent lymph leaks out into thorax.
What does a chylothorax cause?
Can compromise respiratory function. Also disrupts lymphocytes migratory pathway and a lymphopenia may develop.
How do malignant cells cause tumour formation in lymphoid tissue?
Attempt to metastasis via lymphatics, become trapped, establish 2ry sites of tumour formation.
Once lymphadenopathy identified what is the 1st thing it is important to determine?
Generalised vs Localised.
How do you diagnose a generalised lymphadenopathy?
Always FNA. Core biopsy/ Excisional biopsy. Haem- lymphopenia (viral), neutrophilia w/ L shift (bacterial), eosinophilia (parasites)
What are the differentials for a generalised lymphadenopathy?
Lymphoma
Reactive LNs to systemic infection
What are the differentials for a localised lymphadenopathy?
Reactive to localised infection
Lymphadenitis
2ry metastatic tumour
How does a reactive LN look on histopathology?
Normal architecture w/ increased cellularity. Secondary follicles w/ germinal centres in response to Ag.
What is lymphadenitis?
An inflammatory reaction due to an active infection within the LN itself.
How does lymphadenitis look on histopathology?
Similar to reactive LN except areas of pyogranulomatous inflamm also present. Suppurative, caseous or granulomatous
What is an example of an organism that causes suppurative lymphadenitis?
Streptococcus equi (strangles)- abscess in LNs.
What is an example of an organism that causes caseous lymphadenitis?
Corynebacterium pseudotuberculosis (sheep and goats)- more like cottage cheese
What is an example of an organism that causes granulomatous lymphadenitis?
Mycobacterial infection. TB/ Johnes.
How does lymphoma look on histopathology?
Usually complete lack of normal architecture. Large numbers of abnormal lymphocytes present. Mitotic figures (unlikely to see if reactive LN)
How does secondary neoplasia look on histopathology?
Areas of normal lymphoid tissue infiltrated by neoplastic cells (focal or diffuse)
Name some diseases of the spleen.
Trauma/ rupture/ haematoma (e.g. RTA)
Torsion (w/ GDV)
Infarction (nb CSF)
What causes diffuse splenomegaly?
Venous congestion
Lymphoid hyperplasia (systemic infectious/ inflamm/ immune mediated)
Systemic amyloidosis
Neoplasia
What causes nodular splenomegaly?
Nodular hyperplasia (benign- incidental) Abscess/ cyst (infectious) 1ry neoplasia (lymphoma, haemangioma, HSA) Metastatic dz (MCT)
Name some viruses that particularly impact on the lymphoreticular system.
Malignant catarrhal fever (herpes)
CSF
FeLV/ FIV/ CDV/ FIP
EIA
Name some bacteria that particularly impact on the lymphoreticular system.
Bacillus anthracis (anthrax) Mycobacterium bovis (TB)/ MAP (Johnes) Corynebacterium pseudotuberculosis (caseous lymphadenitis)
Name some protozoa that particularly impact on the lymphoreticular system.
Leishmania
Babesia
Ehrlichia
Theileria
What is the link between thymoma and hypercalcaemia?
PTHrp from tumour cells increases bone resorption and distal tubular Ca resorption
What is the link between thymoma and myasthenia gravis?
Tumour may interfere with negative selection of autoreactive T cells, allowing more to leave the thymus. Immune response against an epitope expressed on thymoma cells spills over to NMJ components sharing the same epitope.
What is the classical appearance of sheep LNs with caseous lymphadenitis?
Onion ring appearance resulting from alternate layers of fibrosis and necrosis.
What organism causes caseous lymphadenitis in sheep and goats?
Corynebacterium pseudotuberculosis
How does the presentation of caseous lymphadenitis differ between sheep and goats?
In sheep more often visceral form.
In goats more often occurs as external abscesses around head and neck.
What is the causative agent of chronic lymphadenitis in goats?
Mycobacterium avium paratuberculosis (Johnes disease)
How is chronic lymphadenitis in goats diagnosed?
Granulomas present in the node. Acid-fast staining of a section of the node.
What are the clinical syndromes associated with Johnes disease?
Diarrhoea.
Chronic weight loss.
What are the clinical signs of babesia?
Anaemia
Pipe-stem diarrhoea
Icterus
Haemaglobinuria
How is babesia linked to anaemia in the cow?
Rapid growth and multiplication of parasite in blood w/ extensive erythrocytic lysis
How is babesia transmitted?
Ticks
What cell type in the blood does leishmania multiply in?
Macrophages
What are the clinical signs of leishmania?
Skin disease, enlarged LNs, eye disease, pallor of MMs, enlarged spleen, cachexia, fever, epistaxis
How is leishmania diagnosed?
Suspicion due to clinical signs. Confirmed by ELISA
How is the spleen attached in the abdomen?
Dorsal extremity fixed to cranial abdomen by gastrosplenic ligament. Ventral extremity relatively mobile.
Where does the splenic artery arise from?
Celiac artery
Where does the splenic vein drain to?
Portal vein
Name some important branches of the splenic artery/ vein.
Branches to left limb of pancreas, greater curvature of the stomach (L gastroepiploic), fundus of the stomach (short gastrics)
What are the functions of the spleen?
Red pulp- RBC maintenance, iron metabolism, blood reservoir, haematopoiesis
White pulp- immune function.
When is total splenectomy indicated?
If neoplasia known or suspected.
How is a total splenectomy performed?
Large ventral midline incision. Begin removal at tail end and double ligate and transect all the hilar vessels. At head end try and preserve the short gastric vessels and transect the gastrosplenic ligament.
How is a partial splenectomy performed?
The hilar vessels to the disease portion are ligated and transected. After a few mins an obvious demarcation between ischaemic and normal used as guidline for resection.
What is the quicker technique for a total splenectomy?
Ligate short gastric vessels, L gastroepiploic a+v, splenic a+v distal to branch supplying the pancreas.
What is the association between splenic diseases and cardiac arrhythmias?
Dogs w/ splenic masses have high risk of cardiac arrhythmias, esp those w/anaemia and haemoabdomen
Why are coagulation tests recommended prior to splenectomy?
DIC can occur w/ both neoplastic splenic lesions and splenic torsion.
What is the main complication following splenectomy?
Haemorrhage- monitor vital parameters and PCV/TP regularly post-op
Why are ischaemic pancreatitis and gastritis complications of a splenectomy?
If blood supply to these organs is compromised
Is splenomegaly more commonly localised or generalised in dogs? And cats?
Localised more common in dogs
Diffuse more common in cats
What are the causes of localised splenomegaly?
Non-neoplastic: haematoma, abscess, nodular hyperplasia, infarction, cyst
Neoplasia: benign- haemangioma, leimyoma, fibroma, lipoma; malignant- HSA, FSA, leiomyosarcoma
What are the causes of diffuse splenomegaly?
Infection- bacterial, fungal, viral, parasitic
Congestion- drugs (barbiturates), splenic torsion and/or GDV, RCHF
Neoplasia- acute and chronic leukemia, systemic MCT, lymphoma, multiple myeloma, malignant histiocytosis
Why does diagnosis of a localised splenomegaly often require histopathology rather than FNA?
FNA often produces just blood when aspirating a localised haematoma or HSA
What is the most common malignant splenic tumour in the dog?
Haemangiosarcoma
What are common sites of metastasis for HSA?
Liver, omentum, mesentery, brain, right atrium and subcut tissue
What is the recommended tx for HSA w/out mets and what is the px?
Splenecomy. Expected survival only 3-12 wks
How long does post op chemo prolong the expected survival following splenectomy for HSA?
6 months
How do dogs w/ splenic torsion present?
Progressive abdominal pain, distension and shock. Or chronic form- CS are vague and intermittent
What is the classic appearance of a splenic torsion on ultrasound?
Snowstorm appearance- large anechoic areas
What is the treatment for a splenic torsion?
Pedicle must not be untwisted- remove en mass or gradually divided and ligated.
What is splenic torsion?
Spleen twist on its vascular pedicle occluding hilar vessels–> splenic congestion +/- splenic vessel thrombosis
What is a lymphoma?
Diverse group of malignant neoplasms that originate from lymphoreticular cells.
What has been suggested to increase risk of feline lymphoma?
FeLV +ve status- insertion of retrovirus to DNA–> oncogenic transformation. Immunosuppression may play a role
FIV +ve status- immunosuppression
What is the anatomic predilection site for lymphoma in dogs and cats?
Dogs- mainly multicentric (multiple LNs)
Cats- mainly gastrointestinal
How does multicentric lymphoma present?
Peripheral lymphadenomegaly. Often asymptomatic- lethargy, malaise, weight loss, anorexia, pyrexia, PD/PU if hypercalcaemic
What are ddx for multicentric lymphoma?
Disseminated infection- lymphadenitis Immune mediated dz Other haematopoietic tumours (leukemia, myeloma) Metastatic/ disseminated neoplasia Generalised skindz Sterile granulomatous lymphadenitis
How does feline lymphoma usually present?
Single LN/ regional LN enlargement is more common than multiple. More likely to be systemically unwell cf dogs.
How does gastrointestinal lymphoma (common in cats) usually present?
Weight loss, anorexia, v+ and/or d+
Localised mass, or multifocal/ diffuse thickened loops of intestine +/- mesenteric LN enlargement on exam
What are the 2 forms of alimentary lymphoma in cats?
High grade- mass lesions with rel short hx of illness, may have signs of GI obstruction. Median age 10YO
Low grade- diffuse thickening of intestinal loops or mild lymphadenomegaly, may be more chronic hx. Median age 13YO
What are the ddx for alimentary lymphoma?
IBD, other GI tumours, FB, intussuception
What are the clinical signs of mediastinal lymphoma?
Dyspnoea, coughing, increased RR (tachypnoea), weight loss, lung sounds decreased ventrally, pooss dysphagia- regurgitation, heart sounds displaced caudally, loss of compressibily, caval syndrome, horners
What are the other sites of lymphoma i.e. extranodal?
Renal CNS/spinal Nasal/ nasopharyngeal Laryngeal/ tracheal Cutaneous Occular
How does renal lymphoma present?
Large irregular kidneys (often bilateral), signs of kidney dz e.g. PD/PU, anorexia, weight loss
Is extranodal lymphoma more common in dogs or cats?
Cats
What are the clinical signs of nasal/ nasopharyngeal lymphoma?
Chronic nasal discharge (serosanguinous to mucopurulent), epistaxis, sneezing, stertor, anorexia, facial deformity, exophthalmus, epiphora
Is cutaneous lymphoma more common in dogs or cats?
Dogs
What are the 2 forms of cutaneous lymphoma?
Epitheliotropic- very superficial epidermis affected
Non-epitheliotropic- deeper layer of skin, sparing the epidermis
What are the 3 stages of the epitheliotropic form of cutaneous lymphoma?
Scaling, alopecia, pruritis–>
Erythematous, thickened, ulcerated, exudative–>
Proliferative plaques and nodules w/ progressive ulceration
What are the clinical signs of ocular lymphoma?
Uveitis, blepharospasm, infiltration, haemorrhage, retinal detachment
What paraneoplastic syndromes can be seen with lymphoma?
Hypercalcaemia
Hypergammaglobulinaemia
Haematological abnormalities- anaemia, thrombocytopenia
How does hypercalcaemia of lymphoma present?
PU/PD due to NDI (Ca interferes w/ action of ADH in kidney)
Dehydration, depression, lethargy, weakness, V+, constipation, bradycardia/ bradydysrhytmias, muscle tremors, RF may occur if left untreated
Which LN is it best to avoid when taking FNA for dx and why?
Submandibular- shows reactive change to mouth
How is lymphoma graded, what is the usual grade for dogs vs cats?
High grade- large cells (blasts)
Low grade- small lymphocytes
Dogs- more are high grade
Cats- intestinal lymphoma can be low or high
What is immunophenotyping?
Assesses markers expressed on cell surface
T cell: CD3+, CD4+, CD8+
B cell: CD79a+, CD21+
Why do you immunophenotype lymphoma?
May affect tx plan Affects prognosis (dogs)
How does immunophenotyping affect prognosis?
T cell usually worse prognosis than B cell for high grade lymphomas. Some low grade T cell lymphomas can have prolonged survival.
Why is haematology essential prior to chemotherapy?
Ensure there are adequate neutrophils and platelets. Check for anaemia. Also gives an indication of BM involvement.
Why is biochemistry essential prior to chemotherapy?
Indicates organ involvement (disease extent and drug metabolism)- liver enzymes, urea and creatinine. Also paraneoplastic syndromes- hypercalcaemia.
What is stage I lymphoma?
Involves a single LN
What is stage II lymphoma?
Multiple regional LNs involved in a regional area
What is stage III lymphoma?
Generalised LN involvement
What is stage IV lymphoma?
Liver +/or spleen involvement (+/- stage III)
What is stage V lymphoma?
BM involvement +/- other organs
What is the substage of lymphoma?
Substage a- w/out systemic signs
Substage b- w/ systemic signs
How do you assess BM involvement in lymphoma?
Abnormal circulating cells or cytopenias in >1 cell line
When is surgery indicated as tx for lymphoma?
Rare. Solitary site lymphoma (good for Hodgkins like lymphoma in cats), acute intestinal obstruction
When is radiation therapy indicated as tx for lymphoma?
Nasal lymphoma
Oral lymphoma
Solitary Lesions
What are the tx options if the O doesn’t want chemo?
Corticosteroids e.g. prednisolone for palliation (effect short lived, 2-3m)
Why should you not pre-treat w/ steroids if you are planning to give chemo?
Corticosteroids promote multi-drug resistance.
Can use as part of combo protocol from outset
Why are corticosteroids used in chemo protocols?
Prednisolone and dexamethasone cause lymphocyte apoptosis
What are the most common lymphoma chemo protocols?
COP based
CHOP based
What does the COP based protocol incl?
Cyclophosphamide
Vincristine
Prednisolone
What does CHOP based protocol contain?
Cyclophosphamide
Doxorubicin
Vincristine
Prednisolone
What is cyclophosphamide’s role in lymphoma chemo protocol?
Alkylating agent- substitutes alkyl chain for H+ ions in DNA causing cross-linkage and breakage of DNA strands- interfere w/ replication and transcription. Not cell cycle specific
What is vincristine’s role in lymphoma chemo protocol?
Mitotic spindle inhibitor- binds to tubulin–> metaphase arrest. G2/M specific
What is prednisolone’s role in lymphoma chemo protocol?
Apoptosis of lymphoid and mast cells
What is doxorubicin’s role in lymphoma chemo protocol?
Anti-tumour abx, inhibits topoisomerase II, break and cross link DNA strands. Not cell-cycle specific.
How do COP and CHOP (M-W) protocols compare with regards to cost?
Initial outlay more w/ M-W.
Can work out similar over time
How do COP and CHOP (M-W) protocols compare with regards to adverse effects?
A bit more likely with M-W than COP
What are the adverse effects of doxorubicin?
Cardiotoxocity in dogs (use ECG)
Mast cell degranulation (rare)
Nephrotoxicity in cats
Vesicant if injected perivascularly (apply ice)
How do COP and CHOP (M-W) protocols compare with regards to first remission duration?
Longer with M-W
How do COP and CHOP (M-W) protocols compare with regards to median survival?
Longer w/ M-W but can be similar w/ COP depending on rescue protocols used
On M-W 20-25% of Ds will live >2y
What is the induction protocol of COP in dogs?
C: 50mg/m2 PO q48hr
O: 0.5-0.7mg/m2 IV q7d
P: 40mg/m2 PO daily wk 1 then 20mg/m2 q48hr
How long is the induction phase of COP protocol used for and what next?
If in remission after 8 weeks, go onto maintenance protocol
What is the maintenance protocol of COP in dogs?
C: 20mg/m2 PO q14d
P: 20mg/m2 PO q48hr
What is usually incorporated in COP protocol in cats for renal/CNS lymphoma?
Cytosine arabinoside- on d1 as IV infusion over 4-12hr. Repeat in wk 4.
How does the COP protocol differ in cats from dogs?
50mg cyclophosphamide can’t be split. Therefore usually given as pulse dose 200mg/m2 in wk 1 and wk 4 (usually one 50mg tab for most cats)
What is the usual maintenance protocol of COP in cats?
Chlorambucil 20mg/m2 q14d and pred 20mg/m2 PO q48hr.
What is the protocol for feline low grade GI lymphoma?
Chlorambucil 20mg/m2 q2w
Pred 40mg/m2 q24hr for 7d then 20mg/m2 EOD
Supplement B12 inj if necc
Rescue- cyclophosphamide or lomustine
What is the modified LOPP protocol?
Lomustine/ vincristine/ pred/ procarbazine
For high grade T-cell lymphomas
What are the options for low budget protocols which don’t involve injectables?
Pred alone- 40mg/m2 daily q7d then 20mg/m2 EOD
Pred plus chlorambucil 20mg/m2 q14d (monitor haem q6-8w)
Lomustine 50-70mg/m2 q21d in Ds, 50mg/m2 q14d in Cs +/- pred (monitor for myelosuppression, hepatotoxicity)
How do you monitor response of LNs to chemo?
By PE
CR= LNs not enlarged
PR= >30% reduction in mean sum longest diameters
PD= >20% increase in sum of longest diameters
SD= between PR and PD
Why is regular haematology important for monitoring patients receiving chemo?
Check for myelosuppresion ideally before each tx in induction phase
What action should be taken in patient receiving chemo has a neutrophil count of <2x10^9/L?
Delay tx for 5-7d
What action should be taken in patient receiving chemo has a neutrophil count of <0.5x10^9/L?
Reduce dose of implicated drug by 20-25% next time
What action should be taken in patient receiving chemo has a neutrophil count of <1x10^9/L?
Consider prophylactic abx
Consider dose reducion by 10-25% next time
What action should be taken in patient receiving chemo has a platelet count of <75x10^9/L?
Delay tx for 5-7d
Why is regular biochemistry important for monitoring patients receiving chemo?
Monitor abnormal parameters e.g. Ca.
Organ function- renal/hepatic
Toxicity- e.g. ALT in patients on lomustine (hepatotoxicity)
Why is regular UA important for monitoring patients receiving chemo?
SG- renal funcyion
Dipstick/ sediment to check for haemorrhagic cystitis
Increased risk of infection
When is echocardiography used in monitoring patients receiving chemo?
Offer prior to doxorubicin- screen for heart dz, assess contractility (FS), esp if exceeding 180mg/m2 cumulative dose
What is recommended for the management of GI disturbances following chemo?
Bland diet, little and often
Gut protectants, anti-emetics (maropitant, metoclopramide, ondansetron), probiotics, metronidazole can be useful for D+
What is recommended for the management of anorexia following chemo?
Antiemetics
Gut protectants
Appetite stimulants- cyproheptadine, mirtazepine
Feeding tubes?
What is recommended for the management of myelosuppression following chemo?
Abx if neutrophils <1x10^9/L e.g. TMS orally
For the febrile neutropenic crisis: BS abx, IVFT, ideally culture open wounds, gut protectants, barrier nurse
What is recommended for the management of haemorrhagic cystitis following chemo?
Stop cyclophosphamide. Change to chlorambucil or melphalan, GAGs, NSAIDs if not on steroids, oxybutinin
What are negative prognostic indicators for lymphoma?
T cell (high grade). Substage b. Hypercalcaemia. Prolonged pre-tx w/ corticosteroids. > Stage III (vs I +II). Stage V (some studies). Site- primary GI (except for colorectal which can do well), pure hepato-splenic, renal. Failure to achieve CR.
In general do cats have better or worse response rate to COP/ CHOP than dogs?
Response rate lower than dogs.
Less predictable- remission 3-8m, survival times variable 3-10m.
What are negative prognostic indicators for cats w/ lymphoma?
Failure to achieve complete response, FeLV +ve, high grade vs low grade, LGL lymphoma (large granular lymphocyte lymphoma subtype)
What do you do when lymphoma relapses if not currently on tx?
Restart original protocol
What do you do when lymphoma relapses if animal receiving a less intensive maintenance protocol?
Go back to original induction protocol
What do you do when lymphoma relapses during induction protocol?
Use new drugs that tumour has not been exposed to before. Preferably in combo. e.g. L-asparaginase + lomustine
DMAC protocol.
How you manage para-neoplastic hypercalcaemia?
Prompt dx and management of lymphoma. Saline diuresis (0.9% NaCl) at 6mls/kg/hr (if no CI). Once rehydrated into furosemide at 1-2mg/kg to promote calciuresis. Tx underlying cause.
What is leukemia?
Malignant neoplasm originating from haematopoietic precursors in BM (or spleen). Neoplastic cells be present in the circulation in large numbers
What are the 2 types of leukemia?
Lymphoid or myeloid- depending on which cell line is involved.
What cells come from the myeloid line?
Megakaryocyte (thrombocytes), erythrocyte, mast cell, basophil, neutrophil, eosinophil, monocyte (macrophage)
What cells come from the lymphoid line?
Natural killer cell
T lymphocyte
B lymphocyte (plasma cell)
How is acute leukemia characterised?
Aggressive- rapid. Immature, poorly differentiated cells (blasts) w/ high capacity to divide. Px poor.
How is chronic leukemia characterised?
Slow progression, mild signs. Well differentiated late precursor cells, w/ less capacity to divide. Px reasonable (several months to years)
How do you differentiate ALL from stage V lymphoma?
ALL- usually sicker, more profound cytopenias on haem and milder lymphadenomegaly
Flow cytometry- ALL CD34 +ve
Which has a poorer px ALL or stage V lymphoma
ALL has poorer prognosis than stage V lymphoma
What are the clinical signs of leukemia?
Non-specific. Lethargy, weakness, anorexia, GI signs, mild generalised lymphadenopathy, hepatosplenomegaly.
Signs related to myelophthisis- fever, petechial haemorrhages, pallor. Sometimes signs of hypercalcaemia
How do you diagnose leukemia?
Cytopenias, often in >1 cells line, abnormal circulating cells
If abnormal cells circulating dx can be made using flow cytometry. May require BM aspirate +/- core.
What is the treatment for acute leukemias?
Tx difficult due to severe cytopenias. Poor px.
ALL: L-asparaginase/ pred, cytarabine, lymphoma type protocol
AML: cytarabine
What is the treatment for chronic leukemias?
Much better success rate and px.
CLL- chlorambucil and pred, MST 1y
CML (rare)- hydroxycarbamide
How do clinical signs, haem and flow cytometry differ between stage V lymphoma and ALL?
Stage V lymphoma- often rel well, LNs often grossly enlarged, cytopenias tend to be mild, CD 34-ve on flow
ALL- often sick, LNs mildly enlarged, cytopenias tend to be marked, CD34+ on flow
What is a myeloma?
Plasma cell tumour, starting in BM (spleen) in older animals
What are the clinical signs of myeloma?
Pyrexia, lethargy, pallor, lymphadenopathy, hepatosplenomegaly, signs of bone pain
Signs of hyperviscosity (due to Ab production)- neurological, bleeding
What is the classic haem/ biochem and UA for myeloma?
Mild non-regenerative anaemia, cytopenias
Hyperglobulinaemia often present due to Ab production by plasma cells (monoclonal spike on serum protein electrophoresis), +/- hypercalcaemia.
UA- Ig light chains (bence-jones proteinuria)
What do radiographs of myeloma often show?
Osteolytic lesions (vertebrae, pelvis, long bones) or diffuse osteopenia
How do you dx and tx myeloma?
Dx: excess plasma cells in marrow- BM aspirate/ biopsy
Tx: melphalan and pred (Ds)
MST: 12-18m in Ds
How does tx of myeloma differ between dogs and cats?
Cats- melphalan can cause marked myelosuppression. Tend to use chlorambucil and pred- px worse
What is polycythaemia vera?
Proliferation of erythroid cell series in marrow, with differentiation to mature RBC