HAEMATOLOGY & ONCOLOGY Flashcards
Where is Hb made? What is needed to make it?
Bone marrow
Iron
Where and how is iron absorbed?
As Fe2+ (ferrous) in the duodenum and jejunum - if stomach acid is reduced e.g. by PPIs then absorption may be impaired.
What is the soluble form of iron?
Ferrous
What form of iron exists in the blood?
Ferric ions
What is transferrin saturation?
Serum iron/total iron binding capacity
When is serum iron highest?
Morning
After iron containing meal
What is the total iron binding capacity?
Space available for iron molecules to bind to transferrin
What is the most common cause of anaemia in children? And adults?
Coeliac
Iron deficiency
Give four causes of iron deficiency.
Inadequate intake of iron
Inadequate absorption
Loss of iron e.g. bleeding
Increase requirements e.g. pregnancy
What should be considered if patients present with a DVT and stroke?
Septal defect (ASD/VSD)
What are the risk factors of DVT?
• Immobility • Recent surgery • Long haul flights • Pregnancy • Hormone therapy with oestrogen (combined oral contraceptive pill and hormone replacement therapy) • Malignancy • Polycythaemia • Systemic lupus erythematosus Thrombophilia
Name 7 thrombophilia’s that predispose patients to developing blood clots.
• Antiphospholipid syndrome (this is the one to remember for your exams) • Antithrombin deficiency • Protein C or S deficiency • Factor V Leiden • Hyperhomocysteinaemia • Prothombin gene variant Activated protein C resistance
When should patients receive VTE prophylaxis?
Increased risk of VTE
Name two contraindications to VTE prophylaxis.
Active bleeding
Warfarin
What is the main contraindication to compression stockings?
PVD
What alternative diagnoses should be considered if symptoms are bilateral?
Heart failure
Chronic venous insufficiency
How do you examine for leg swelling?
Measure both calves, 10cm below the tibial tuberosity.
If they are >3cm different, DVT is likely.
What scoring system is used to determine the risk of DVT/PE?
Wells
Name 5 other conditions that can cause a raised D-dimer.
• Pneumonia • Malignancy • Heart failure • Surgery Pregnancy
Under what circumstances should a negative proximal leg Doppler scan be repeated? When should it be repeated?
If scan is negative, but D-dimer is positive, repeat the scan in 6-8 days.
What is the initial management of a DVT?
Enoxaparin SC
What is the target INR for treatment using warfarin?
2-3
What is the first-line choice of prophylaxis in patients with pregnancy or cancer?
LMWH
How long should anti-coagulation be continued after a DVT?
3 months - if reversible cause identified.
>3 months - if no identifiable cause.
6 months - cancer.
What is the treatment for recurrent DVTs?
IVC filter (prevents PE)
Can also be used if anti-coagulation is contraindicated.
How should an unprovoked DVT be investigated?
• History and examination • Chest X-ray • Bloods (FBC, calcium and LFTs) • Urine dipstick • CT abdomen and pelvis in patients over 40 Mammogram in women over 40
If patients have an unprovoked DVT and a family history of DVT, how do you investigate?
In patients with an unprovoked VTE with a family history of VTE they recommend testing for hereditary thrombophilia:
• Factor V Leiden (most common hereditary thrombophilia)
• Prothrombin G20210A
• Protein C
• Protein S
Antithrombin
What is Budd-Chiari syndrome?
Blood clot develops in the hepatic vein blocking the outflow of blood. It is associated with hypercoagulable states and causes acute hepatitis.
What is the triad of symptoms seen in Budd-Chiari syndrome?
Abdominal pain
Hepatomegaly
Ascites
Name 3 chronic myeloproliferative disorders.
- Polycythaemia vera.
- Primary myelofibrosis (also called chronic idiopathic myelofibrosis).
- Essential thrombocythemia.
What is the pathophysiology of myeloproliferative diseases?
Proliferation of a single type of stem cell.
Considered to be bone marrow cancer.
What condition do myeloproliferative disorders transform into?
Acute myeloid leukaemia
What is myelofibrosis?
Proliferation of the cell line leads to fibrosis of the bone marrow.
The bone marrow is replaced by scar tissue.
Fibrosis affects the production of blood cells leading to anaemia and leukopenia.
What cytokine causes myelofibrosis?
Fibroblast growth factor
What is extramedullary haematopoiesis? What are the signs of haematopoiesis?
Blood cells are produced outside of the bone marrow.
Mostly in the liver and spleen.
Leading to hepatosplenomegaly.
Can also cause portal hypertension and spinal cord compression.
Which cell line proliferates to cause primary myelofibrosis?
Haematopoietic stem cells
Which cell line proliferates to cause PCV?
Erythroid cell line
Which cell line proliferates to cause essential thrombocythemia?
Megakaryocytic cell line
Which genes are associated with myeloproliferative disorders? Which gene can be specifically targeted by drugs?
JAK2
MPL
CALR
If a patient presents with back pain and a PMHx of myeloproliferative disorders, what should be suspected?
Spinal cord compression (due to extramedullary haematopoiesis)
How do myeloproliferative disorders generally present?
Asymptomatic
Fever
Weight loss
Malaise
Night sweats
How do myeloproliferative disorders generally present?
Asymptomatic
Fever
Weight loss
Malaise
Night sweats
What are the three key signs on examination in suspected PCV?
Ruddy complexion
Conjunctival plethora
Splenomegaly
What are the findings on FBC in PCV?
High Hb
What might be seen on an FBC in myelofibrosis?
Low Hb
Low WCC or high WCC
Low platelets or high platelets
What are the findings on FBC in ET?
High platelets
What is seen on blood film in myeloproliferative disorders?
Tear-shaped RBCs Poikilocytosis (varying size RBCs) Blast cells (immature WBCs)
What investigation is needed for a definitive diagnosis of myeloproliferative disorders?
Bone marrow biopsy
What is found on bone marrow aspiration in primary myleofibrosis?
Dry (due to scar tissue)
What is the management of primary myelofibrosis?
Mild = monitor
Allogenic stem cell transplantation
Chemotherapy
Supportive management
What is the management of PCV?
Venesection - first-line
Aspirin (VTE prophylaxis)
Chemotherapy
What is the management of essential thrombocythemia?
Hydroxyurea (hydroxycarbamide) to reduce the platelet count
Interferon-α is in younger patients
Aspirin (VTE prophylaxis)
Chemotherapy
How is aspirin used in the management of myeloproliferative disorders?
VTE prophylaxis
Which cell lines are affected in leukaemia?
Myeloid
Lymphoid
What are the four types of leukaemia?
Acute lymphoblastic leukaemia
Chronic lymphocytic leukaemia
Acute myeloid leukaemia
Chronic myeloid leukaemia
How does leukaemia lead to pancytopenia?
The excessive production of a single type of cell can lead to suppression of the other cell lines causing underproduction of other cell types.
This results in a pancytopenia, which is a combination of low red blood cells (anaemia), white blood cells (leukopenia) and platelets (thrombocytopenia).
What is the mnemonic used to remember the different ages that each type of leukaemia presents?
ALL CeLLmates have CoMmon AMbitions
ALL = <5 years old and >45 years old CLL = >55 years old CML = >65 years old AML.= >75 years old
What are the typical features that a patient with leukaemia might present with?
• Fatigue • Fever • Failure to thrive (children) • Pallor due to anaemia • Petechiae and abnormal bruising due to thrombocytopenia • Abnormal bleeding • Lymphadenopathy Hepatosplenomegaly
What are petechiae? Why are they found in leukaemia?
Small, non-blanching spots due to bleeding under the skin.
Caused by low platelets - thrombocytopenia.
What investigation should be done if there is central nervous system involvement in leukaemia?
LP
What investigations are used for staging of leukaemia?
CT
MRI
PET
What might be seen on CXR of a patient with leukaemia?
Infection
Mediastinal lymphadenopathy
Where are bone marrow biopsies taken from?
Iliac crest
What is the difference between a bone marrow aspiration and trephine?
Aspiration = liquid sample, can be examined straight away Trephine = solid sample, takes a few days to be examined
Which two features should prompt immediate referral to hospital in suspected leukaemia?
Petechiae
Hepatosplenomegaly
Name some complications of chemotherapy.
Infections Infertility Neurotoxicity Cardiotoxicity Tumour lysis syndrome
What is tumour lysis syndrome?
Release of uric acid.
Kidneys normally excrete uric acid before levels can build up. High levels form crystals in the tubules of the kidney.
What drugs are used to treat tumour lysis syndrome?
Allopurinol and rasburicase.
What is a characteristic symptom of ET?
Burning sensation in the hands