Haematology Flashcards
What is the general clinical presentation of anaemia?
Non-specific symptoms:
- Fatigue, headaches, faintness, dyspnoea, breathlessness, angina, anorexia, intermittent claudification, palpitations
Signs:
- May be absent
- Pallor, tachycardia, systolic flow murmur, cardiac failure
What is the aetiology of microcytic anaemia?
- iron deficiency anaemia
- anaemia of chronic disease
- thalassaemia
- lead poisoning
What is the aetiology of iron deficiency anaemia?
- blood loss (GI bleeding, menorrhagia, hookworm)
- poor diet
- increased demands (e.g. during growth and pregnancy)
- malabsorption (poor intake, coeliac disease)
What is the pathophysiology of iron deficiency anaemia?
Less iron is available for haem synthesis therefore less haemoglobin is made, leading to smaller RBCs
What are the risk factors of iron deficiency anaemia?
- undeveloped countries
- high vegetable intake
- premature infants
- delayed introduction of mixed feeding in infants
- hookworm infection
- coeliac disease
What is the clinical presentation of iron deficiency anaemia?
- general anaemia symptoms
- brittle nails and hair
- spoon-shaped nails
- atrophy of papillae on tongue
- ulceration of the corner of the mouth
What are the differential diagnoses of iron deficiency anaemia?
- thalassaemia
- sideroblastic anaemia
- anaemia of chronic disease
How is iron deficiency anaemia diagnosed?
- blood count and film (small, pale RBCs and variation in RBC shape and size)
- low serum ferritin
- low serum iron
- low reticulocyte count
How is iron deficiency anaemia managed?
- find and treat cause
- oral iron (e.g. ferrous sulphate)
- parenteral iron (e.g. IV iron in extreme causes)
What is the pathophysiology of anaemia of chronic disease?
- decreased release of iron from the bone marrow to developing erythroblasts
- inadequate erythropoietin response to anaemia
- decreased RBC survival
What is the main risk factor of anaemia of chronic disease?
Having a chronic disease
How is anaemia of chronic disease diagnosed?
- low serum iron and total iron-binding capacity
- normal or raised serum ferritin
- blood count and film (RBCs are normal/ microcytic and pale)
How is anaemia of chronic disease managed?
- treat underlying cause
- give erythropoietin to raise haemoglobin level
What is the aetiology of normocytic anaemia?
- acute blood loss
- anaemia of chronic disease
- endocrine disorders (e.g. hypopituitarism, hypothyroidism or hypoadrenalism)
- renal failure
- pregnancy
How is normocytic anaemia diagnosed?
- normal B12 and folate
- raised reticulocytes
- low haemoglobin
- blood count and film
How is normocytic anaemia managed?
- treat underlying cause
- improve diet with vitamins
- erythropoietin injections
What is the aetiology of macrocytic anaemia?
Megaloblastic and non-megaloblastic
Megaloblastic:
- vitamin B12 deficiency, folate deficiency
Non-megaloblastic:
- alcohol, liver disease, hypothyroidism, haemolysis, bone marrow failure, bone marrow infiltration, antimetabolite therapy, myeloma
What are the risk factors of of folate deficiency anaemia?
- low dietary folate intake
- age > 6y
- alcoholism
- pregnant or lactating
- prematurity
- intestinal malabsorptive disordes
- use of methotrexate
What is the clinical presentation of folate deficiency anaemia?
- prolonged diarrhoea
- loss of appetite and weight
- fatigue
- shortness of breath
- dizziness
- pallor
- tachycardia
- heart murmur
What are the differential diagnoses of folate deficiency anaemia?
- vitamin B12 deficiency
- thiamine-responsive megaloblastic anaemia
- alcoholic liver disease
- hypothyroidism
How is folate deficiency anaemia diagnosed?
- peripheral blood smear
- FBC
- reticulocyte count
- serum folate
- RBC folate
- serum vitamin B12
How is folate deficiency anaemia managed?
- oral folic acid and multivitamin supplementation
- folonic acid
- treat underlying disorder
What is the aetiology of sickle cell anaemia?
type and location of genetic defect
Autosomal-recessive single gene defect in the beta chain of haemoglobin
What is the pathophysiology of sickle cell anaemia?
- RBCs become rigid and distorted in crescent shape
- defamed cells cause vast-occlusion in the small vessels or adhere to vascular endothelium resulting in intimacy hyperplasia in larger vessels, slowing blood flow
What is the risk factor for sickle cell anaemia?
- family history (genetic)
What is the clinical presentation of sickle cell anaemia?
- persistent pain in skeleton, chest and/or abdomen
- dactylitis (inflammation of the digits)
- high temperature
- pneumonia-like syndrome
- bone pain
- visual floaters
What are the differential diagnoses of sickle cell anaemia?
- gout
- septic arthritis
- connective tissue diseases
- avascular necrosis
How is sickle cell anaemia diagnosed?
- DNA-based assays
- haemoglobin isoelectric focusing
- cellulose acetate electrophoresis
- haemoglobin solubility testing
- peripheral blood smear
How is sickle cell anaemia managed?
- only curative treatment is bone marrow transplantation
What is the aetiology of pernicious anaemia?
B12 deficiency
What are the risk factors of pernicious anaemia?
- elderly
- female
- fair-haired and blue-eyed
- blood group A
- thyroid and Addison’s disease
What is the clinical presentation of pernicious anaemia?
general and neurological features
- insidious onset with progressively increasing symptoms of anaemia
- may have a lemon-yellow skin colour (from pallour and mild jaundice)
- red sore tongue and ulceration of corners of the mouth
Neurological features:
- only occur if B12 is very low
- burning or prickling pain/ tingling in fingers and toes
- early loss of vibration sense and proprioception
- progressive weakness and ataxia
- paraplegia
- dementia, psychiatric problems, hallucinations, delusions
What are the differential diagnoses of pernicious anaemia?
- folate deficiency
- any disease in the terminal ileum or bacterial overgrowth in the small bowel
- gastrectomy
How is pernicious anaemia diagnosed?
- blood count and film (large RBCs that may be oval-shaped on a peripheral film)
- raised bilirubin
- low B12
- low Hb
- low reticulocytes
How is pernicious anaemia managed?
- B12 injections if due to malabsorption
- oral B12 if due to dietary deficiency
What is the aetiology of a DVT?
general, genetic, acquired
- surgery, immobility, leg fracture, oral contraceptive pill, long haul flights, malignancy
Genetic:
- Factor V Leiden, antithrombin deficiency, protein C or S deficiency
Acquired:
- anti-phospholipid syndrome, lupus anticoagulant
What is the pathophysiology of a DVT?
Blood clots develop in the deep vein system of the leg just above and behind a venous vein
What are the risk factors of a DVT?
- increasing age
- pregnancy
- synthetic oestrogen
- hospitalisation within the past 2 months
- major surgery within 3 months
- recent long haul flights
- active cancer
- lower extremity trauma
What is the clinical presentation of a DVT?
- may be asymptomatic
- calf swelling
- localised pain along deep venous system, often with swelling, redness and engorged superficial vein
- affected calf is often warmer and there may be ankle oedema
- asymmetric anaemia
- complete occlusion can cause cyanotic discolouration of the limb and severe oedema
- pulmonary embolism can also occur (more frequent from an iliofemoral thrombosis)
How is a DVT diagnosed?
- Wells’ score
- plasma D-dimer level
- proximal Duplex US
- whole-leg US
How is a DVT managed?
- low molecular weight heparin (e.g., sc enoxaparin)
- oral warfarin
- direct acting Oral Anti-Coagulants (DOAC)
- compression stockings
- inferior vena cava filters to reduce risk of pulmonary emboli
Prevention:
- early mobilisation post-op
- compression stockings
- thromboprophylaxis for low and high risk
What is the aetiology of leukaemia?
Presence of rapidly proliferating immature blast blood cells in the bone marrow that are non-functional
What is the pathophysiology of leukaemia?
Bone marrow is not able to make as many normal functioning cells resulting in fewer functioning blood cells in the blood
What is the aetiology of acute lymphoblastic leukaemia?
- increased proliferation of immature lymphoblast cells (B cells in children, T cells in adults)
- combination of genetic susceptibility and environmental trigger
What is the clinical presentation of acute lymphoblastic leukaemia?
Marrow failure
- low Hb → breathlessness, fatigue, angina, clarification, pallor
- low WCC → infections, fever, mouth ulcers
- low platelets → bleeding and bruising
- bone pain from bone marrow infiltration
- headache and cranial nerve palsies from CNS infiltration
- hepatosplenomegaly from liver/ spleen infiltration
How is acute lymphoblastic leukaemia diagnosed?
- FBC and blood film → high WCC, blast cells on film and in the bone marrow
- CXR and CT scan to look for mediastinal and abdominal lymphadenopathy
- lumbar puncture to look for CNS involvement
How is acute lymphoblastic leukaemia managed?
- blood and platelet transfusions
- allopurinol
- prophylactic antivirals, antibacterial and antifungals
- IV fluids through a Hickman line
- chemotherapy
- marrow transplantation
What is the aetiology of acute myeloid leukaemia?
Neoplastic proliferation of blast cells derived from marrow myeloid elements
What is the clinical presentation of acute myeloid leukaemia?
Marrow failure
- low Hb → breathlessness, fatigue, angina, clarification, pallor
- low WCC → infections, fever, mouth ulcers
- low platelets → bleeding and bruising
- hepatomegaly and splenomegaly
- gum hypertrophy
- disseminated intravascular coagulation
What is the differential diagnoses of acute myeloid leukaemia?
Acute lymphoblastic leukaemia
How is acute myeloid leukaemia diagnosed?
- WCC often raised, but can be normal or low
- may be blast cells in the peripheral blood so diagnosis depends on bone marrow biopsy
- differentiation from acute lymphoblastic leukaemia is based on microscopy, immunophenotyping and molecular methods
How is acute myeloid leukaemia managed?
- blood and platelet transfusions
- allopurinol
- prophylactic antivirals, antibacterial and antifungals
- IV fluids through a Hickman line
- chemotherapy
- marrow transplantation
What is the aetiology of chronic lymphoblastic leukaemia?
- accumulation of mature B cells that have escaped apoptosis and undergone cell-cycle arrest
- may be triggered by pneumonia
What is the clinical presentation of chronic lymphoblastic leukaemia?
- often asymptomatic and found on routine FBC
- may be anaemic or infection prone
- if severe, then weight loss, sweats and anorexia
- hepatosplenomegaly
- enlarged, rubbery, non-tender nodes
How is chronic lymphoblastic leukaemia diagnosed?
- FBC - normal/ low Hb, raised WCC (very high lymphocytes)
- blood film - smudge cells may be seen in vitro
How is chronic lymphoblastic leukaemia managed?
- blood transfusions
- human IV immunoglobulins
- chemo/radiotherapy
- try a stem cell transplant
What is the aetiology of lymphoma?
- primary immunodeficiency: ataxia telangiectasia, Wiscott-Aldrich syndrome
- secondary immunodeficiency: HIV, transplant recipients
- infection: EBV, H.pylori
- autoimmune disorders e.g SLE
What are the risk factors of Hodgkin’s lymphoma?
- affected sibling
- EBV
- SLE
- obesity
- post-transplantation
What is the clinical presentation of Hodgkin’s lymphoma?
- painless cervical lymphadenopathy (commonly described as rubbery)
- may present with generalised disease (weight loss, fever, night sweats)
Emergency presentation:
- infection
- superior vena cava obstruction with increased venous jugular pressure
- dyspnoea
- blackouts
- facial oedema
How is Hodgkin’s lymphoma diagnosed?
- CT/ MRI for chest, abdomen and pelvis for staging
- lymph node for excision or bone marrow biopsy
- bloods: high ESR or low Hb indicated worse prognosis
- PET scan
- cytogenetics
- immunophenotyping
How is Hodgkin’s lymphoma managed?
Combination therapy (ABVD):
- adriamycin
- bleomycin
- vinblastine
- dacarbazine
What is the risk factor of non-Hodgkin’s lymphoma
Family history
What is the clinical presentation of non-Hodgkin’s lymphoma?
- nodal disease
- extra nodal disease
- systemic B symptoms: fever, night sweats, weight loss
- pancytopenia: anaemia, infection and bleeding
How is non-Hodgkin’s lymphoma diagnosed?
- marrow and node biopsy
- CT/MRI of chest, abdomen and pelvis for staging
- lymph node excision or bone marrow biopsy
- cytogenetics
- immunophenotyping
- cytogenetics
How is non-Hodgkin’s lymphoma managed?
R-CHOP regimen:
- rituximab
- cyclophosphamide
- hydroxydaunorubicin
- oncovin
- prednisolone
What is the aetiology of malaria?
Protozoa from Plasmodium transmitted to humans through a bite from one of the 40 species of female Anopheles mosquitos
What is the pathophysiology of malaria?
Mosquito infects malaria sporozoites during a blood meal which enter hepatocytes
What are the risk factors of malaria?
- travel to endemic area
- inadequate or absent chemoprophylaxis
- low host immunity
- pregnancy
- age <5y
- immunocompromised
- older age
What is the clinical presentation of malaria?
- headache
- weakness
- myalgia
- arthralgia
- anorexia
- diarrhoea
- seizures
What are the differential diagnoses of malaria?
- dengue fever
- Zika virus infection
- yellow fever
- pneumonia
- influenza
How is malaria diagnosed?
- Giemsa-stained thick and thin blood films
- rapid diagnostic tests
FBC - clotting profile
- serum electrolytes, urea and creatinine
- serum LFTs
- serum blood glucose
How is malaria managed?
- depends on the infecting species
- no treatment until diagnosis is confirmed
- antimalarial drugs e.g. hydroxychloroquine
- multiple agents are used to avoid selective resistance
