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183 Cards in this Set
- Front
- Back
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Haematopoiesis starts here
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Haematopoiesis starts here
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What is haematopoiesis?
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The process by which the various mature blood cells types are produced from haematopoietic stem cells
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What are the 3 factors that are required of haematopoietic cells in terms of haematopoiesis?
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Commitment
Proliferation Maturation |
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How many types of mature cells can the haematopoietic stem cells produce and what are they?
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8 types (at least)
Myeloid cell line: - granulocytes (basophils, neutrophils, eosinophils) - rbcs - platelets (thrombocytes) - monocytes -> macrophages (also dendritic cells in this lineage) Lymphoid - T-cells - B-cells |
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Where do the haemopoietic stem cells originate?
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Foetal yolk sac
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Is there a difference between where haematopoiesis occurs at birth to where it occurs in an adult? Explain
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Birth: bone marrow, (minor: liver spleen, kidney)
Adult: bones (+ erythropoiesis in spleen) |
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In which bones does haematopoiesis occur in the adult?
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Proximal ends of long bones
Skull Spine Ribs Sternum Pelvis |
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What is the main stimulation factor and what is the main hormone in Erythropoiesis?
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Erythropoietin (from the kidney) is the main growth factor
Its release is primarily stimulated by low tissue oxygenation ie hypoxia |
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What are the 3 causes of hypoxia?
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Hypoxia
Decreased no of RBC or Hb Low enviro oxygen availability Decreased O2 uptake ie lung disease, CHF |
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What is extramedullary haematopoiesis?
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Haematopoiesis outside the bone marrow - confined to erythropoiesis in the adult (spleen)
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What would it mean if you saw reticulocytes or nucleated RBC in a blood smear?
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Hypoxia -> release of immature red blood cells into the peripheral blood
- to meet the demand for increased rbcs |
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What are the normal % that reticulocytes & nucleated RBC make up in blood? What % may you see in hypoxia?
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Reticulocytes
normally = 1% hypoxia = 30-50% Nucleated RBC normally = 0% hypoxia = 5-20% |
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There are 2 important phases that bone marrow cells are found in. What are they and what are their normal ratios?
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Proliferative 25%
Maturation 75% |
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In what situation would you see a proportional increase in the number of cells in the maturation phase of haematopoiesis?
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Ineffective haematopoiesis (iron deficiency & chronic maturation of rbcs)
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In what 3 conditions would you see an increase in the number of marrow cells in the proliferative phase?
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Active regeneration
Leukemia Ineffective haematopoiesis |
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There are 4 essential elements required for erythropoiesis. Name them and their chief importance.
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1. Vit B12 – RBC production & DNA synth
2. Folic acid – as above 3. Iron – incorporated in haemaglobin 4.Copper – converts ferrous iron to ferric iron allowing it to bind to transport plasma protein. |
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Anaemia starts here
- disorders of erythropoiesis, leukopoiesis & thrombopoiesis |
Anaemia starts here\
- disorders of erythropoiesis, leukopoiesis & thrombopoiesis |
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What is anaemia?
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Anaemia is the decreased ability of the blood to supply tissues with adequate O2.
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List some common causes of Anaemia
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Blood loss
Haemolytic diseases Hereditary disorders of RBC production Acquired disorders of RBC production |
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Regenerative anaemia arises from 2 situations (sometimes remembered as the 2 H’s), what are they?
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HAEMORRHAGE & HAEMOLYSIS
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Anaemia can be classed in 2 ways. What are they and what do they mean?
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1. Regenerative
Evidence the bone marrow is responding to decreased PCV 2. Non-regenerative Characterised by decreased or ineffective RBC production |
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There are 3 factors that can be used to help characterise blood in Anaemia. What are they?
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Decreased total RBC
Decreased haematocrit (PCV) Decreased haemaglobin |
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If a dog is presented to you following a haemorrhagic injury (say a ‘hit by car’) & it has evidence of reticulocytes & nucleated RBC in a blood smear, should you be concerned?
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Despite your concern for the patient, evidence of immature RBC is good as it indicates the bone marrow is responding to the injury.
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How would this differ if it was a horse or cat?
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Horses DONT release reticuloccytes
Cats only release MATURE reticulocytes |
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What 2 other ways can you classify anaemia's?
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Size of the RBC
- macrocytic, normocytic, microcytic Amount of Iron - normochromic, hypochromic |
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So there are 3 major ways of classifying anaemia
they are... |
1. Regenerative or non-regenerative
2. SIZE of RBC 3. Amount of Fe |
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There are 4 main classes of anaemia discussed in the notes, what are they?
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1. Hereditary
2. Haemorrhagic 3. Haemolytic 4. Acquired |
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What are the 2 most common hereditary disorders of RBC production discussed in class
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Familial anaemia of Basenji Dogs
Pyruvate kinase deficiency, short RBC life span (3 days) Congenital porphyria - Abnormal metab of porphyrins (basic comp of molecules that contain haem) - Deposition of porphyrins in skin -> photosensitization |
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How is haemorrhagic anaemia classed & list some common causes
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Anaemia – Haemorrhagic
Acute/chronic Internal/external Trauma, ectoparasites, neoplasms, gastric ulcers (all causing blood loss) |
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Why are young animals particularly sensitive to acute severe blood loss?
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Young animals have no iron reserves. Will lead to non-regenerative anaemia unless bleeding stops or iron is given
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Under what circumstances will rbc size and iron content be apparently normal on a blood smear despite severe haemorrhage?
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IMMEDIATELY after haemorrhage, anaemia will be normocytic & normochromic
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What are some examples of toxic agents capable of causing anaemia?
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Bracken fern
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What are the two general sites at which rbc destruction can occur?
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Intravascular & extravascular
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When do haemolytic anaemias occur in respect to RBC production?
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When RBC production < RBC destruction
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What are the 3 haemolytic anaemias we discussed?
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1. Immune mediated
2. Infectious haemolytic 3. Non infectious haemolytic (Rape, Kale, Pb, Cu) |
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Outline IMHA
Give examples of causative agents (4) What happens in foals? |
Antibodies to RBC -> spherocytes (reduced life span)
Aetiological agents incl. Viruses, drugs, autoimmune, idiopathic Eg. Isoimmune haemolytic anaemia in foals dt anti foal RBC antibodies from the mare via colostrum. |
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List at least 4 causative pathogens of infectious haemolytic anaemia
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Equine Infectious Anaemia Virus
Babesia – intracellular protozoa Anaplasma – intracellular ricketsia Eperythrozoonsis - rickettsia Haemobartonella Ehrlichiosis - rickettsia Trypansoma |
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What are some examples of non-infectious haemolytic anaemias.
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rape or kale
Onions – cattle, horses & dogs Copper – acute haemolysis Lead – fragility of RBC & inhib of haem synth |
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What are the 4 general causes of acquired disorders of erythropoiesis that were discussed
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1. Infectious – parvo etc
2. Toxic – Brackern fern etc 3. Nutritional – Fe (generally 2ndary to chronic blood loss, with hypochromic & microcytic - Cu (decreased haem synth & iron transportation) - Co (decreased vit B12 synth in ruminants) 4) Secondary - starvation/chronic, - uraemia – dt decreased EPO, increased blood loss in urine etc |
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What is Polycythaemia? AKA erythrocytosis
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Increased RBC production
(Strictly Polycythaemia can be used to refer to an increase in all blood cell types) |
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What are the 2 classifications of erythrocytosis?
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1) Absolute – true increase in RBC
2) Relative – most common – total no. Is normal but increased PCV dt dehydration & haemoconcentration |
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What is erythropoiesis?
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The generation of mature RBC from haemopoietic stem cells in the marrow.
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What are the 2 classifications of absolute polycythaemia? Give examples
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Primary – rare – neoplastic prolif of erythrocytes
Secondary – appropriate (hypoxaemia) & inappropriate (EPO doping, renal neoplasm w EPO, paraneoplastic syndrome w incr. EPO-like) |
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What are the 2 classes of disorders of leukopoiesis?
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1. Myeloproliferative
2. Myelodysplastic syndromes |
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What are myeloproliferative disorders?
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Medullary/extramedullary proliferation of one or more blood cell lineages (excluding lymphoma & lymphoid leukaemias)
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How do the bone marrow, spleen & liver appear in response to a myeloproliferative disorder?
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Bone marrow – expansion of marrow spaces with red, firm marrow at the expense of fat
Spleen – meaty & enlarged Liver – diffuse infiltration of neoplastic cells -> swollen & pale |
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In which of our domestic animals will you tend to see myeloproliferative diseases?
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Myeloproliferative diseases occur mostly in DOGS & CATS
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What is the difference in the expected life span for acute & chronic leukaemias?
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Acute = 1-2 months
Chronic = 1-3 years |
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Try to name the 5 examples myeloproliferative disorders
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1. Erythrocytic – iie erythemic myelosis, & erythroleukaemia,
2. Granulocytic - any of the 3 lineages can beocme neoplastic but neutro = most common 3. Monocytic 4. Megakaryocytic 5. Plasmacytic – you can get plasma cell sarcomas (irregular soft pink masses in marrow cavities), which are different from the BENIGN plasmacytosis that is common in the skin of dogs, often around the digits and nose. |
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What was the 2nd disorder of leukopoiesis and outline the main points?
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Myelodysplastic syndromes
Diverse group Characterized by refractory cytopenias (def in blood cells) – anaemia, leukopaenia, &/or thrombocytopaenia accompanied by dysplastic changes in the marrow of one or more cell lineages |
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What's the difference between lymphoma & leukaemia?
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Lymphoma: malignant lymphoid cells
- primarily affecting lymph nodes or solid visceral organs (liver, spleen) Leukemia: malignant haematopoietic cells -> in BM, clonal proliferation replaces fat - often infiltrates tissues (liver, spleen, lymph nodes) |
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How are leukemias classified?
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How are leukaemias classified?
Acute/chronic Chronic leukamias = more differentiated -> easier to recognise Myeloid/ lymphoid lineages (with mAbs) |
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What are thrombocytes and what are the 3 main disorders of thrombopoiesis?
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Thrombocytes = platelets
The 3 disorders are 1. Platelet functional disorders 2. Thrombocytopaenia 3. Thrombocytosis |
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What is thrombocytosis?
When is it seen? |
Increased no. of platelets in blood
Usually reactive ie following haemorrhage or splenectomy, infections etc |
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What is "thrombocytopaenia?
Give the 2 basic causes and an example of each |
Thrombocytopaenia = reduced no. of platelets dt
1. Premature destruction, eg immune-mediated, infection, DIC 2. Decreased production, eg drug induced bone marrow suppression or toxicities |
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What is the main platelet functional disorder?
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VWD
Most common canine hereditary disorder |
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What is the consequence of vWD?
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vWD is released by damaged endothelium & facilitates platelet adhesion to stop bleeding. Thus, the consequence is a primary haemostatic disorder.
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Spleen starts here
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Spleen starts here
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What is the largest mass of lymphatic tissue in the body?
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Spleen
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Functions of spleen (5)
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Filter blood thru sinusoidal system
Remove effete rbcs & platelets Store rbcs & platelets & iron Extramedullary haematopoietic site Site of antigenic stimulation |
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Structure of spleen (4)
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Thick capsule of smooth m & connective (+elastic)) tissue
Penetrates parencyhma (red pulp & white pulp) Sinusoids lined with phagocytic cells Efferent lymphatics only |
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What are the 5 key elements of RED pulp?
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Basic: sinusoids that drain into splenic cords
Details: 1) penicilliar arteriole 2) marcophage ensheathed capillaries 3) Sinusois 4) Reticular cells (marcophage like) 5) All cell types of circulating blood |
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What is RED PULP?
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The spongy reticular meshwork of sinusoids which open into splenic chords
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What is white pulp?
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Central artery, PALS (T cells) , lymph nodules (B cells)
Lymph nodules have a germinal centre when active |
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Does the spleen play a role in haematopoiesis?
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Yes = important extramedullary haematopoietic site.
Also an important storage site of immature RBC |
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What does the spleen filter and how is this different to lymph nodes?
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The spleen filters blood whereas lymph nodes filter lymph. There are no afferent lymphatics in the spleen only efferent.
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In which animals do you most commonly see splenic torsion?
Consequences? |
Large breed dogs
Pigs Humans Rare in horses If it twists on its mesentry -> congestion & haemorrhagic infarction -> necrosis |
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When do you see splenic rupture and what are the consequences?
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Trauma
Splenomegaly occ. Spleen readily heals -> scaring & lines of fissure – can get seeding of ruptured splenic tissue > accessory spleens |
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What part of the spleen does amyloidosis typically effect most?
How does the spleen appear? |
Germinal centres
Spleen appears pale & cut surfaces appear waxy |
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What would you see in fatty infiltration? Is it incidental?
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Usually incidental
Extends into parenchyma & occurs in areas where capsule is adherent to mesenteries |
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What are the key features of siderotic plaques?
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Incidental
Brown/yellow encrustations along splenic margins = Fe & Ca deposits |
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What do you see in senile atrophy?
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Thickened capsule with lymphoid atrophy. Seen in dogs & horses – may be 2ndary to startvation
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What are the 6 degenerative disorders of the spleen?
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1. Senile atrophy
2. Siderotic plaques 3. Fatty infiltration 4. Amyloidsois 5. Splenic rupture 6. Splenic torsion |
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Which animals have a spleen with both large storage and defence ability?
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Dogs and cats > ruminants > rabbits
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Degenerative diseases of the spleen (6)
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senile atrophy
siderotic plaques fatty infiltration amyloidosis ("sago") rupture torsion |
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Neoplasia of the spleen (3)
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Primary;
lymphosarcoma haemangiosarcoma mast cell (esp cats) |
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In which of our domestic animals do you see mast cell tumours? How does the spleen look grossly?
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Cats – diffusely enlarged, purple/choc colour & meaty texture.
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How would you recognise a patient with a splenic haemangiosacroma?
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Spleen appears nodular, enlarged, spongy & red/black
Pleomorphic spindle cells on histo |
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Where do haemangiosacromas originate from & what is the main concern about them?
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Arise from vascular endothelium
Freq metastasize to liver, lungs & widely Can rupture leading to metastatic seeding to peritoneal surfaces |
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How can a splenic lymphosarcoma appear?
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Nodular or diffusely enlarged spleen
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What are the 3 most likely neoplasms of the spleen?
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Lymphosarcoma
Haemangiosarcoma Mast cell tumour RGS note: Haemangiosarcoma is often seen in practice as dogs present with a ruptured spleen with anaemia and haemoabdomen |
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Splenomegaly
- 2 types? |
Nodular or diffuse
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Nodular splenomegaly (5)
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hyperplasia
haematoma (esp after trauma, thrombosis, infarction) parasitic cysts (Taenia) bacterial abscesses (Arcanobacterium) neoplasia (lymphosarcoma, haemangiosarcoma, metastasis) |
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Diffuse splenomegaly (5)
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congestion
hypersplenism (dt pancytopaenia) reactive (lymphoid) hyperplasia (dt chronic antigenic stimulation) amyloidosis neoplasia (primary or secondary) |
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What effect does hypersplenism, or any condition resulting in splenomegaly, have on the organs phagocytotic potential?
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Increased! -> haemolytic anaemia, thrombocytopaenia, leucopenia
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what does hypersplenism mean?
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The association between blood pancytopaenia & splenic enlargement
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There are heaps of possible causes for splenic congestion. Name at least 5
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Barbituates
Passive congestion (circ disturb systemic, portal vasc) Torsion Acute systemic infection Salmonella, anthrax, ASF, erysipelas etc |
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How do acutely congested spleens tend to appear? How is this different to chronic congestion?
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Acute = dark, enlarged, ooze on cut section
Chronic = firm parenchyma with thickened capsule |
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We discussed 5 types of diffuse spleenomegaly, can you remember
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1. Congestion
2. Neoplasia 3. Hypersplenism 4. Reactive hyperplasia 5. Amyloidosis |
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Name 1 parasitic cyst & 1 bacterial abscess that can occur in the spleen.
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Taenia hydatigena
Rodococcus equi in horse Arcanobacterium pyogenes in cows |
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How do haematoma appear grossly and on cut surface?
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Single/multiple dark red spongy nodules above the capsular surface
Collapse with leakage of blood once cut (usually) |
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How can you tell that it is nodular hyperplasia and is therefore benign?
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Based on behaviour, not on histo
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What are the important points about nodular hyperplasia?
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Common in older dogs
Solitary or multiple Rise above capsular surface On cut surface they appear red or white with necrotic foci |
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What are the 4 types of nodular spleenomegaly discussed?
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1. Nodular hyperplasia
2. Haematoma 3. Parasitic cysts & bacterial abscesses 4. Neoplasia |
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What are the 2 broad categories of spleenomegally?
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Diffuse or nodular
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What is reactive hyperplasia of the spleen?
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Chronic antigenic stimuli hyperplastic white pulp & expansion of red pulp
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Thymus starts here
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Thymus starts here
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Thymus - 2 major tissue components
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lymphoid tissue
epithelial tissue |
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Functions of thymus (1)
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T cell selection
- leave thymus to populate lymph nodes, spleen, peripheral blood |
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Hassall's corpuscles
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Distinctive feature of thymus;
- eosinophic staining - rosettes of degenerated/ing reticular cells - function unknown |
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Thymic medullary cells
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Less tightly packed thymoctyes
Hassall's corpuscles |
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Thymic cortical cells
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Tightly packed thymocytes
Site of intense lymphopoiesis |
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Thymus site
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Cranial mediastinum
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What is SCID?
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Autosomal recessive condition where B and T lymphocyte function is absent
- ALL lymphoid tissue is hypoplastic |
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SCID
- breeds most affected |
Arabian horses
Basset hounds, Springer spaniels, JRT, corgis Mice (KO?) |
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Myasthenia gravis
- what is it? - CS? - how does it arise? |
Autoimmune disorder
- abs to AChR - muscle weakness, reduced exercise tolerance - often arises spontaneously in association with thymoma |
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Myasthenia gravis
- relationship to thymus? |
Often associated with thymoma dt
- benign lymphoid proliferation |
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Paraneoplastic syndrome
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Disorders arising from metabolic effects of cancer on tissues remote from the tumour
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Inflammatory diseases of the thymus (2)
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Myasthenia gravis
Infectious inflammation |
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Common causes of infectious inflammation of thymus;
- dogs - horses - cats - cattle |
Dogs: distemper, parvovirus
Horses: EHV1 Cats: parvovirus, FeLV, FIV Cattle: BVDV (all target rapidly dividing cells) |
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Thymoma
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Slow growing tumor of the thymic epithelium
- accompanied by benign lymphoid proliferation |
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Thymoma - gross features
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Slow growing, heavily encapsulated, multi-nodular tumour
- oft. anterior mediastinum - rarely metastasize |
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Thymic lymphoma
- what? - where in body? - effects? - growth? |
Tumour dt lymphoid cells of thymus
- can grow to VERY large size in anterior mediastinum - cause compression of neighbouring structures - rarely metastasise - often infiltrate beneath sternal pleura |
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Degenerative disorders of the thymus (4)
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Toxins that target dividing cells
Ionising radiation Corticosteroids Starvation (dt decr. leptin!) |
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Thymic lymphoma - gross features
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Poorly encapsulated tumour
- young animals, esp cats, dogs, cattle - rarely metastasize - anterior mediastinum - grow to a large size - compression of oesophagus, trachea, lungs |
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Thymoma - histologic features
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Mediastinal growth with neoplastic thymic epithelial cells
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Thymic lymphoma - histologic features
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Mediastinal growth with neoplastic thymic lymphoid cells.
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Most common mediastinal growth
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Mediastinal lymphoma (not thymoma, not thymic lymphoma)
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What are the 3 common types of neoplasia of the thymus?
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Thymoma
- slow growing, heavily encapsulated, multinodular, rarely metastisize Thymic lymphoma - grow large compression, poorly encapsulated, rarely metastasize Lympoid thymoma - resp/cardiovas signs in dogs & horses, incidental in sheep & goats |
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What are 2 inflammatory diseases of the thymus?
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1. Myasthenia gravis – Ab against achetyl-choline receptors
2. Infectious inflam of the thymus Distemper Parvo EHV BVD |
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What is the condition that occurs in arabian foals?
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SCID = severe combined immunodef dis
Autosomal recessive Appear normal at birth until ~10days diarrhoea, pneumonia death |
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What is congenital immunodeficiency?
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An absence or defect in a class or subclass of lymphocytes from either the bone marrow.
If both T & B cells are involved = combined immunodeficiency |
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There are 3 types of disease of the thymus that we discussed in class, what are they?
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1. Developmental disease
2. Inflammatory 3. Neoplasia |
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What is the distinctive feature of thymic tissue called?
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Hassels corpuscles in medulla (function unknown)
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Once the T4 (helper cells) & T8 (cytotoxic cells) develop, where do they go ?
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Some in the bloods but most Populate the paracortical areas of the lymph nodes & the periarteriolar sheaths of the spleen
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Why is only 99% of lympopoiesis in the thymus ineffective?
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Immunologic selection based on MHC expression -> high rate of apoptosis
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When does the thymus reach its maximal size & what happens thereafter?
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Puberty incompletely regresses into adult life
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What are the 2 distinct anatomical regions of the thymus?
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Cortex & medulla
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The thymus is a composite organ of what 2 tissues?
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Epithelial & lymphoid
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Lymph nodes starts here
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Lymph nodes starts here
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What does local/regional lymph node enlargement usually reflect?
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Local inflammatory or neoplastic processes
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What is enlargement of lymph nodes termed?
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Lymphadenopathy
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What is the purpose of dendritic cells & macrophages in lymph nodes?
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Trapping, digestion & antigen processing & presentation
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How do the T & B cells exit the lymph node?
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Via high endothelial venules
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Do efferent or afferent lymphatics enter the lymph nodes?
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Afferent
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What makes up the medulla of lymph nodes?
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Cords & sinuses packed with plasma cells
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Which important cell is located in the paracortex?
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T cells
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What is the mantle zone?
What is found there? |
The mantle zone surrounds the germinal centre of lymph nodes & consists of immunological naive B cells
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What is in the cortex of lymph nodes
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Cortex
- follicles of - B lymphocytes - Macrophages - Dendritic cells Follicles can be primary or secondary. Secondary follicles contain a germinal centre |
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Which domestic animal has the cortex/paracortex as the inner portion & medulla as the outer?
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pig
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What are the 3 regions of lymph nodes?
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1. medulla
2. cortex 3. paracortex |
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Acute lymphadenitis
- what is it? - where is it seen? |
Lymphadenitis (inflammation of the lymph node with infectious agent present).
Acute lymphadenitis is almost exclusively seen in nodes DRAINING the infected focus with pyogenic bacteria infections - the bacteria may or may not be colonising the lymph node |
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2 causes of reduced lymph node size
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SCID
atrophy |
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Lymph node regions (3) and main cells
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cortex: B-cells, APCs, macrophages
- site of follicles paracortex: developing T-cells medulla (nearest hilus): cords & sinuses with lymphocytes, plasma cells and macrophages |
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Lymphadenopathy
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Regionalised or generalised enlargement of lymph nodes
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Why is it important to determine if lymphadenopathy is localised or generalised
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Localised lymphadenopathy
- inflammatory or local neoplastic Generalised lymphadenopathy - systemic infectious disease or neoplasia |
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Reactive follicular hyperplasia
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Proliferation of lymph node in response to antigen stimulation
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How do you distinguish reactive follicular hyperplasia from neoplasia?
GROSS |
Reactive follicular hyperplasia:
- enlarged Neoplasia - enlarged, soft, white-yellow, may be haemorrhage & necrosis - may be oedema in draining tissue |
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Lymphadenitis
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Inflammation of the node with the aetiological agent present
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What is a common cause of acute lymphadentiis in (young) horses
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Strangles is a common cause of acute ____ in (young) horses
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Acute lymphadentiis
- gross and histological features |
Acute lymphadenitis
Gross: Enlarged swollen nodes, exude pus & lymph on cut Histo: neutrophil dominated reaction, fibrin exudates, oedema, hyperaemia |
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Chronic lymphadentiis
- gross and histological features |
Chronic lymphadentiis
Gross: enlarged, firm Histo:macrophage dominated reaction, also plasma cells. Areas of fibrosis. Granulomas or abscesses |
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6 common causes of chronic lymphadenitis in domestic species
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Tuberculosis: Mycobacterium bovis
Caseous lymphadenitis (sheep): Corynebacterium pseudotuberculosis Johne's Disease: M. avium paratuberculosis Wooden tongue: Actinobacillus lignieresi Actinomyces pyogenes Protozoas: Leishmania, Histoplasma, Theileria |
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Why are lymph nodes a major site of tumour metastasis (particularly carcinoma & malignant melanoma)?
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Guessing that it's because carcinoma and malignant melanoma are loosely adhered tumour - individual cells or small groups circulate and end up trapped in lymph node?
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Distinguish reactive follicular hyperplasia from lymphoma
- histo |
Reactive Follicular Hyperplasia
- mixed plasma cell population - follicles vary in shape - node architecture maintained but germinal centres larger Lymphoma - uniform lymphocyte population - node architecture lost |
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What's the difference between reactive follicular hyperplasia and lymphadenitis?
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Both reactive follicular hyperplasia and lymphadenitis occur secondary to antigenic stimulation.
Lymphadentitis - aetiological agent is present |
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Lymphomas can arise in which organs?
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Lymphomas can arise in any haematopoetic tissues'
- lymph nodes, spleen, thymus, bone marrow, liver Other tissues including intestine (GALT), kidney, skin, etc Also ? |
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Lymphoma
- usual gross appearance |
Gross appearance of lymphoma
- large, soft, white-yellow - poss. necrosis & haemorrhage - poss. oedema of draining tissue |
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How are lymphomas classified?
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Classification of lymphomas
- architecture - cell size - nucleus shape - nucleolus size, shape, number - chromatin pattern - cytoplasmic volume, density, placement |
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Features of lymphomas with;
- slow progression - fast progression |
Lymphomas
slow: small cells with low mitotic index (less responsive to chemotherapy) fast: large cells with high mitotic index (potentially treatable but can be fatal) |
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Infectious disease associated with lymphoma in cats
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FeLV (a retrovirus) is associated with development of ___ in persistent viraemic cats
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Enzootic bovine leucosis
- features |
Bovine lymphoma dt BLV = bovine leukemia virus (retrovirus)
- usually adults - lifelong infection - few develop malignancy |
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Sporadic bovine leucosis
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Bovine lymphoma of unknown aetiology
- usually under 3 y Juvenile form - cattle under 6 mo - multicentric |
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In general, the prognosis for a dog with lymphoma is poor.
T/F |
True - most lymphomas in dogs are disseminated and of high grade
Tendency of paraneoplastic syndromes |
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Characteristics of lymphoma in sheep & pigs
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Lymphoma in sheep: sim to bovine juvenile form: widely disseminated, aetiology unknown
Lymphoma in pigs: most common tumour. Inherited in Large Whites. Die due to associated bone marrow failure |
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Myeloma
- common presentation |
Plasma cell tumour
- commonly present as single or multiple bone tumours arising within the bone marrow -secrete Igs |
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How can urinalysis assist in making a diagnosis of myeloma?
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Bence-Jones proteins (immunoglobulin light chains) in the urine are indicative of _____
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Hemal nodes (species)
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Looks like a lymph node, functions like a spleen.
- ruminants & rats |
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Paraneoplastic syndrome
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Disorder arising from metabolic effects of cancer on tissues remote from the tumour
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Cachexia
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Profound ill-health and malnutrition with wasting?
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Likely cause of haemorrhagic lymph nodes in cattle
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Bacillus anthracis is the likely cause of ____ lymph nodes in cattle
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In what condition of horses do lymph nodes often appear swollen and jet black?
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Horses with malignant melanoma often have lymph nodes that are ____
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What does lymphadenopathy suggest?
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Neoplastic disease, or
Systemic infection |
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Could you easily tell the difference between a hyperplastic lymph node & lymphoma?
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Not easily
Gross: lymphoma maybe soft, white/yellow , possible necrosis, haemorrhage, oedema Histo: loss of architecture and uniform population of cells for lymphoma |
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How would you tell the difference between reactive follicular hyperplasia of a lymph node & lymphadenitis?
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In lymphadenitis the aetiological agent is present in the lymph node - may/may not be seen.
Lymphadenitis: acute - may see suppurative reaction (neutrophil) chronic - may see granulomatous reaction (macrophage) |
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Lymphadenitis can be acute & chronic, how would the lymph nodes appear in each?
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Acute -> swollen, haemorrhagic, exude pus & lymph on cut (neutrophil infiltration)
Chronic -> enlarged, firm, cortical expansion, may have focal lesions eg granulomas or abscesses |
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What is the most common cause of acute lympadenitis?
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Pyogenic infections ie strep, fancisella
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What are some examples of chronic lymphadenitis?
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1. Actinobacillus lignieresi – wooden tongue
2. Mycobacterium avium paratuberc – Johnes 3. Corynebacterium ovis – CLA 4. Mycobacterium bovis –tuberculosis |
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What is the most common factor preceding haemorrhage of lymph nodes?
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Vascular endothelial damage
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Lymphoma AKA LYMPHOSARCOMAS are common in domestic animals. What tissues do lymphomas commonly affect?
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Haemopoietic tissues – bone, spleen, lymph nodes, marrow, kidney, heart etc
Robin's note LYMPH NODES especially |
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How do lymphomas appear grossly?
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Soft, white/yellow masses
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What happens to the general architecture of the nodes in lymphoma?
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It is lost
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Remember to add pix prior to path prac exam
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Remember to add pix prior to path prac exam
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