Flashcards in Oncology and haematology ||| Deck (127):
At what age is the peak incidence of acute lymphoblastic leukaemia?
What is the cause of the symptoms of ALL?
Result of disseminated disease and infiltration of the bone marrow or other organs with leukaemic blast cells
What are the generalised symptoms of ALL (2)?
What symptoms are caused by bone marrow inflitration in ALL (4)?
1. Bone pain
2. Anaemia -> Pallor, lethargy
3. Neutropenia -> Infection
4. Thrombocytopenia -> Bruising, petechiae, nose bleeds
What symptoms are caused by reticulo-endothelial infiltration in ALL (3)?
3. Superior mediastinal obstruction (uncommon)
What symptoms are caused by other organ infiltration in ALL?
1. CNS -> Headaches, vomiting, nerve palsies
2. Testes -> Testicular enlargement
What ages are Neuroblastomas and Wilms tumours seen in?
Investigations of neuroblastoma/Wilm's?
Management of neuroblastoma/Wilm's?
First 6 years of life
1. CT abdo
2. increased urinary catecholamines
3. BM sample
4. MIBG scan
1. Localised - surgery
2. Metastatic (likely)
chem, stem cell rescue, surgery/radio
Prognosis -> poor, high relapse, low cure rate
1. USS and or CT/MRI (tumour of mixed density)
2. Chest X-ray -> lung metastasis
2. Delayed nephrectomy, radio for advanced
Prognosis -> Good 80% cured, 60% for metastatic. If relapse, poor
What ages do Hodkin lymphoma and bone tumours peak in?
Adolescence and early adult life
What investigations would be done to investigate ALL and what would their findings be (5)?
-evidence of circulating leukemic blast cells
2. Bone marrow sample - essential for diagnosis + identify immunological and cytogenic characteristics
3. Clotting screen - 10% have DIC
4. LP - identify disease in CSF
5. Chest X-ray to identify a mediastinal mass characteristic of T-cell disease
6. Blood film -> blast cells
What is the initial management of ALL, aimed at preserving life (3)?
1. Blood transfusion:
-to correct anaemia and reduce risk of bleeding with platelets
2. Treat any infection
What is the treatment regime available for ALL (4)?
1. Remission induction:
-Combination chemotherapy including steroids given. Remission implies eradication of the leukaemic blasts and restoration of normal marrow function
-Followed by a block of intensive chemotherapy to consolidate remission
3. Intrathecal chemotherapy given to prevent CNS relapse
4. Continuing therapy:
-Chemotherapy of modest intensity is continued for up to 3 years
-co-trimoxazole for PCP prophylaxis
What are the high risk prognostic factors in ALL (5)?
1. Age <1 year or >10 years
2. Tumour load >50 x 10^9 (white cell count)
3. Cytogenetic/molecular genetic abnormalities in tumour cells e.g. MLL rearrangement
4. Persistence of leukaemic blasts in the BM after inital chemotherapy
5. Detectable minimal residual disease (MRD) after induction therapy
What are lymphomas? What are the 2 types?
Malignancies of the cells of the immune system
Hodgkin and non-Hodgkin lymphoma
What age group are Hodgkin and non-Hodgkin lymphoma most common in?
Hodgkin = adolescents
Non-Hodgkin = childhood
What cells does Hodgkin lymphoma arise from?
How does Hodgkin lymphoma present (3)?
1. painless lymphadenopathy, usually in the neck
-large and firm, may cause airway obstruction
2. History is usually long (several months)
3. B symptoms i.e. fever, sweating etc are rare
1. LN biopsy
2. Radiology CT C/A/P +/- PET
3. BM biopsy
What is the main difference between non-Hodgkin and Hodgkin lymphoma?
Hodgkin lymphomas contain Reed-Sternberg cells (broken B cell) seen under the microscope. Non Hodgkin lymphomas do not.
What cells does non-Hodgkin lymphoma arise from?
What blood cell cancers can T-cell malignancies present as (2)?
2. non-Hodgkin lymphoma
What blood cell cancers can B-cell malignancies present as?
Usually non-Hodgkin lymphoma
How does non-Hodgkin lymphoma present as:
T cell malignancy (5)
B cell malignancy (2)
T cell - usually characterised by a mediastinal mass with bone marrow infiltration
1. Mass can cause SVC obstruction
3. Facial swelling and flushing
4. Venous distension in neck
5. Distended veins in upper chest and arms
1. Localised lymph node disease usually in the head/neck/abdomen
2. Abdominal disease can present with pain from intestinal obstruction, a palpable mass or intussusception
1. LN biopsy
3. BM exam
4. CSF analysis - ?CNS involvement
What are long-term complications of tumour treatment i.e. chemo/radiotherapy/surgery (6)?
2. Growth - undernutrition
5. Tumour lysis sydrome - dehydration K+ PO4 and urate increase, Ca2+ low
6. Neutropenic sepsis - life threatening sepsis due to decreased WCC after chemo
What is a sarcoma?
Tumour of conective tissue such as muscle or bone
What is the most common form of sarcoma?
Rhabdomyosarcoma = tumour of striated muscle
What are the more common sites for soft tissue sarcomas to present in and the symptoms they cause there (3)?
1. Head and neck
-bloodstained nasal discharge
2. GU system
-blood stained vaginal discharge
3. Metastatic disease (lung, liver, bone)
What age are osteoscarcomas more common in?
How do osteosarcomas present (3)?
1. Usually present in the limbs
2. Persistent localised bone pain = characteristic symptom
3. Followed by detection of a mass
What is an Ewing sarcoma?
A malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue around bone
Symptoms of Ewing sarcoma (5)?
1. bone pain – this may get worse over time and may be worse at night
2. a tender lump or swelling
3. fever that doesn't go away
4. feeling tired all the time
5. weight loss
What is a retinoblastoma?
What age does it typically present at?
How does it present?
A malignant tumour of retinal cells
Within first 3 years of life
White pupillary reflex replaces the normal red, or with squint
What is the site of haemopoiesis in fetal life and in postnatal life?
Post-natal: Bone marrow
What type of haemoglobin is present on the fetus? What chains are they made up of?
Fetal haemoglobin (HbF)
2 alpha chains and 2 gamma chains (a2g2)
What are the 3 types of haemoglobin present at birth?
How is HbF different from adult Hb (HbA)?
HbF has a higher affinity for O2 than HbA, an advantage in the relatively hypoxic environment of the fetus
How does the Hb composition change in the first year of life?
HbF is gradually replaced by HbA and HbA2
Why are neonates asymptomatic with types of inherited anaemia?
The presence of HbF is protective in the first few months
What can an increased proportion of HbF indicate (2)?
2. Bone marrow failure
What is HbA2? How is it different from HbA?
HbA2 is a normal variant of HbA found in low levels in the blood.
HbA is made up of 2alpha chains and 2beta chains
HbA2 is made up of 2alpha chains and 2delta chains
What are the haematological values at birth and first few weeks of life?
1. At birth, Hb is high = 140g/L to 215g/L.
This falls due to reduced red cell production to reach 100g/L at 2 months (lowest level).
2. WBC in neonates are higher than older children = 10-25x10^9/L
3. Platelet counts at birth are within normal adult range = 150-400x10^9/L
Why is the concentration of Hb higher at birth?
To compensate for the low O2 concentration in the fetus
What are the normal haematological values during childhood (2-6)?
Hb: 115-135 g/L
Platelet: 150-450x10^9 at all ages
What are the normal haematological values during childhood (6-12)?
Hb: 115-135 g/L
What are the normal haematological values during childhood (12-18)?
What is the difference in the change in Hb in preterm babies?
There is a steeper fall in Hb to a mean of 65g/L to 90g/L at 4-8 weeks chronological age
How are stores of iron, folic acid and Vit B12 different in preterm babies compared to normal babies? What are the implications of this?
They are adequate at birth but lower and Iron + Vit B12 depleted more quickly, leading to deficiency after 2-4 months if not maintained by supplements
What is the definition of anaemia in:
2. 1-12 months
3. 1-12 years
What are the 3 mechanisms by which anaemia occurs?
1. Reduced red cell production
-red cell aplasia
2. Increased red cell destruction (haemolysis)
3. Blood loss (uncommon in children)
What are the causes of impaired red cell production (2)?
1. Ineffective erythropoiesis
2. Red cell aplasia (complete absence of red cell production)
What are some causes of ineffective erythropoiesis (4)?
1. Iron deficiency
2. Folic acid deficiency
3. Chronic inflammation
4. Chronic renal failure
What are diagnostic clues to ineffective erythropoiesis (2)?
1. Normal reticulocyte count
2. Abnormal mean cell volume (MCV) of red cells:
-low in iron deficiency
-raised in folic acid deficiency
What are the main causes of iron deficiency (3)?
1. Inadequate intake - common in infants
3. Blood loss
Why is inadequate iron intake common in infants? How much does an infant need?
Additional iron is required for the increase in blood volume accompanying growth and to build up the child's iron stores.
Needs about 8mg/day (similar to father)
What foods may iron come from in an infant (4)?
2. Infant formula
3. Cow's milk (but only 10% absorbed)
4. Solids introduced at weaning e.g. cereals
What are the clinical features of anaemia (4)? At what level of Hb do infants and children become symptomatic?
1. Tire easily
2. Feed more slowly
3. May be pale - pale conjunctiva, tongue or palmar creases
What are the diagnostic clues for iron deficiency anaemia (2)?
1. Microcytic, hypochromic anaemia (low HCV and MCH)
2. Low serum ferritin
What is the management of iron deficiency anaemia (2)?
1. Dietary advice, supplementation with oral iron until Hb levels are normal and then for another 3 months to replenish iron stores
2. Investigate malabsorption (Coeliac) or chronic blood loss (e.g. Meckels)
What are the 3 main causes of red cell aplasia?
1. Congenital red cell aplasia
2. Transient erythroblastopenia of childhood
3. Parvovirus B19 infection (if child has an inherited haemolytic anaemia)
What are the diagnostic clues to red cell aplasia (4)?
1. Low reticulocyte count despite low Hb
2. Normal bilirubin
3. Negative direct antiglobin test (Coombs test)
4. Absent red cell precursors on bone marrow examination
What is haemolytic anaemia?
Reduced red blood cell lifespan caused by increased red cell destruction in the circulation/liver/spleen. lifespan goes from a normal 120 days to a few days.
Bone marrow production can increase 8 fold so haemolysis only leads to anaemia when bone marrow is no longer able to compensate.
What are the main causes of haemolysis in children (3) and neonates (1)?
Children: Intrinsic abnormalities of the RBC:
1. Red cell membrane disorders (e.g. hereditary spherocytosis)
2. Red cell enzyme disorders (e.g. G6PD deficiency)
1. Haemolytic disease of the newborn
What are the consequences of haemolysis from increased red cell breakdown (4)?
2. Hepatomegaly and splenomegaly
3. Increased blood levels of unconjugated bilirubin
4. Excess urinary urobilinogen
What are the diagnostic clues to haemolysis (5)?
1. Raised reticulocyte count
2. Unconjugated bilirubinaemia
3. Abnormal appearance of the red cells on a blood film
4. Positive direct antiglobulin test
5. Increased red blood cell precursors in the bone marrow
What is Hereditary spherocytosis?
A red cell membrane disorder leading to haemolytic anaemia. Usually autosomal dominant inheritance, leading to the red cell losing part of its membrane as it passes through the spleen. This causes it to become spheroidal, making them less deformable than normal RBC and causes their destruction in the microvasculature of the spleen.
What are the clinical features of hereditary spherocytosis (7)?
1. Family history
2. Variable clinical manifestations
3. Jaundice - during childhood and may be intermittent
4. Mild anaemia in childhood
5. Mild to moderate splenomegaly
6. Aplastic crisis
How is hereditary spherocytosis diagnosed?
What is glucose-6-phosphate dehydrogenase deficiency?
G6PD is responsible for preventing oxidative damage to red cells.
X-linked so affects males
What are the clinical manifestations of G6PD (6)?
1. Neonatal jaundice
2. Acute haemolysis
5. abdo pain
6. dark urine
Diagnosis of G6PD?
Measuring G6PD activity in RBC
What is a haemoglobinopathy? What are the 2 types?
Red blood cell disorders which cause haemolytic anaemia because of:
1. Reduced or absent production of HbA
-a or b thalassaemias
2. Production of an abnormal Hb
-sickle cell disease
What is sickle cell disease? What is its inheritence?
Sickle cell disease is a collective name given to haemogloinopathies in which HbS is inherited.
HbS forms as a result of a point mutation in codon 6 of the b-globin gene causing a change from the amino acid glutamine to valine.
What are the 3 main forms of sickle cell disease?
What are the carriers (sickle trait)?
1. Sickle cell anaemia (HbSS) - homozygous for HbS, so virtually all Hb is HbS
2. HbSC disease - affected children inherit HbS from one parent and HbC from the other parent (as a result of a different point mutation in b-globin) so they have no HbA.
3. Sickle b-thalassaemia - affected children inherit HbS from one parent and b-thalassaemia trait from the other. They have no normal b-globin genes and most patients can't make any HbA
4. Carriers (sickle trait) - inheritance of HbS from one parent and a normal b-globin gene from the other parent. Patients are carriers but do not have sickle cell dsiease and are asymptomatic, but can transmit HbS to offspring.
What is the pathogenesis of Sickle cell disease?
HbS polymerises within RBC forming rigid tubular spiral bodies which deform the red cells into a sickle shape. These have a reduced lifespan and can be trapped in microcirculation, resulting in blood vessel occlusion and therefore ischaemia in an organ or bone. This is exacerbated by low O2 tension, dehydration and cold.
What factor is important for modifying severity of sickle cell disease?
The amount of HbF. Some patients naturally produce more HbF which results in reduced disease severity.
What are the clinical features of sickle cell disease (5)?
1. Moderate anaemia
2. Increased susceptibility to infection from encasulated organisms such as pneumococci and H. influenzae - due to hyposplenism secondary to chronic sickling and microinfarction in the spleen in infancy
3. Vaso-occlusive crises causing pain affecting many organs of the body, most commonly bones of the limbs and spine.
4. Acute anaemia: sudden drop in Hb from
-haemolytic crisis - sometimes associated with infection
-aplastic crisis - often caused by parvovirus infection
-sequestration crisis - sudden splenic or hepatic enlargement, abdo pain and circulatory collapse from accumulation of sickled cells in spleen.
What are the long-term problems of sickle cell disease (9)?
1. Short stature and delayed puberty
2. Stroke and cognitive problems
3. Adenotonsillar hypertrophy
4. Cardiac enlargement
5. Heart failure
6. Renal dysfunction
7. Pigment gallstones
8. Leg ulcers
9. Psychosocial problems
What screening is available for sickle cell disease in the UK?
Guthrie test - neonatal screening using dried blood spots in first week of life
-Early diagnosis allows for penicillin prophylaxis to be started in early infancy
Pre-natal diagnosis can be done by CVS at end of 1st trimester
What is the management of sickle cell disease (5)?
1. Prophylaxis due to increased susceptibility of infection
2. Avoiding vaso-occlusive crisis by minimising exposure to cold, dehydration, excessive exercise, undue stress or hypoxia
3. Treatment of acute crisis - analgesia, good hydration, infection with Abx, O2
4. Treatment of chronic problems - Hydroxycarbamide to increase HbF production to protect against further crisis.
5. Bone marrow transplant for those severely affected
Which demographic of people is sickle cell most common in?
Black, originate from tropical Africa or the Caribbean
What demographic of people is b-thalassaemia most common in?
Indian subcontinent, Mediterranean and Middle East
What are the 2 main types of b-thalassaemia?
1. b-thalassaemia major - more severe form. HbA (a2b2) cant be produced because of abnormal b-globin gene.
2. b-thalassaemia intermedia - milder form, b-globin mutations allow a small amount of HbA and/or a large amount of HbF to be produced.
What is the pathophysiology of b-thalassaemia?
Single base substitution or small insertions near or upstream of the β globin gene or deletions of different sizes involving the β globin gene leading to:
Reduced or absent synthesis of the beta chains of haemoglobin and therefore a reduction in HbA production.
What does the disease severity of b-thalassaemia depend on?
Amount of resideual HbA and HbF production
What are the clinical features of b-thalassaemia (3)?
1. Severe anaemia - transfusion dependent from 3-6 months and jaundice
2. Faltering growth/growth failure
3. Extramedullary haemopoiesis, prevented by regular blood transfusions.
-without blood transfusions: develop hepatosplenomegaly and BM expansion -> maxillary overgrowth and skull bossing (rare)
What is the management of b-thalassaemia (2) and the long-term complications of it?
1. Fatal without monthly life-long blood transfusions
Complications of repeated blood transfusion:
Chronic iron overload, which, if untreated, can lead to cardiac failure, liver cirrhosis, diabetes, infertility and growth failure.
-> treated with iron chelation
2. Bone marrow transplant
What screening is available for b-thalassaemia?
If parents are both heterozygous for b-thalassaemia trait, there is a 1 in 4 risk of having an affected child. Prenatal diagnosis by chonric villus sample with genetic counselling
What are the clinical features of b-thalassaemia trait?
Heterozygous so are asymptomatic
What is a-thalassaemia?
Healthy people have 4 a-globin genes. a-thalassaemias are the deletions of these genes, so there are no alpha chains produced and a relative excessive of beta chains. The more genes deleted the worse the syndrome is.
What are the different types of a-thalassaemia (£)?
1. a-thalassaemia major/Hb Barts hydrops fetalis - caused by deletion of all 4 a-globin genes so no HbA can be produced - presents in midtrimester with fetal hydrops from fetal anaemia
2. HbH disease - only 3 a-globin genes are deleted, affected children have mild-moderate anaemia but occasional patients are transfusion-dependent
3. a-thalassaemia trait - deletion of one or two a-globin genes is usually asymptomatic and anaemia is mild or absent.
What are the main causes of haemolytic anaemia in neonates (4)?
1. Immune - haemolytic disease of the newborn
2. Red cell membrane disorders e.g. hereditary spherocytosis
3. Red cell enzyme disorders e.g. G6PD deficiency
4. Abnormal Hb e.g. a-thalassaemia major
What is haemolytic disease of the newborn?
Abtibodies against blood group antigens, usually anti-D, anti-A or anti-B. Mother is negative and baby is positive, so the mother makes antibodies against the babys blood group antigen. This crosses the placenta into the baby's circulation causing fetal or neonatal haemilytic anaemia.
What is haemostasis and what components is it made up of (5)?
Haemostasis describes the normal process of blood clotting
1. Coagulation factors
2. Coagulation inhibitors
5. Blood vessels
What are the possible pathophysiological changes that can occur that lead to an increased risk of bleeding (3)?
1. Defects in coagulation factors
2. Defects in platelet number of function
3. Defects in the fibrinolytic pathway
What are the possible pathophysiological changes that can occur that lead to thrombosis (2)?
1. Defects in the naturally occurring inhibitors of coagulation e.g. antithrombin
2. Defects in vessel wall e.g. damage from vascular catheters
What are the possible pathophysiological changes that can occur that lead to disseminated intravascular coagulation (DIC)?
Abnormalities in both procoagulant and anticoagulant pathways
What inital screening tests can be done to investigate a bleeding disorder (8)?
1. FBC and blood film
2. Prothrombin time (PT) - measure activity of Factors II, V, VII and X
3. Activated partial thromboplastin time (APTT) - measures activity of Factors II, V, VIII, IX, X, XI and XII
4. If PT or APTT is prolonged, a 50:50 mix with normal plasma will distinguish between possible factor deficiency or presence of inhibitor
5. Thrombin time - tests for deficiency or dysfunction of fibrinogen
6. Quantitative fibrinogen assay
7. D-dimers - tests for fibrin degredation products
8. Biochemical screen including renal and LFTs
What is the difference in levels of clotting factors in neonates and preterm compared to older children?
All clotting factors except Factor VIII and fibrinogen are lower
Preterm infants have even lower levels
What is haemophilia? What are the different types (2)?
The most common severe inherited coagulation disorders leading to spontaneous bleeding
Haemophilia A - FVIII deficiency
Haemophilia B - FIX deficiency
What is the genetic inheritance of Haemophilia?
X-linked recessive inheritence
What investigations would you do for haemophilia A and what are the results (8)?
1. PT: Normal
2. APTT: Increased
3. Factor VIII:C Decreased
4. vWF Antigen: Normal
5. RiCoF (activity): Normal
6. Ristocetin-induced platelet aggregation: Normal
7. vWF multimers: Normal
8. Family history in 2/3rds
What are the 3 grades of severity of Haemophilia A?
According to level of Factor VIII
What is the hallmark of severe Haemophilia A (2)?
1. Recurrent spontaneous bleeding into joints and muscles
2. which can lead to crippling arthritis if not properly treated
At what age do children usually present with Haemophilia A? How do they present?
What % of children present as neonates?
Towards the end of the 1st year of life, when they start to crawl or walk (and fall over)
How do neonates present with haemophilia A (3)?
1. Intracranial haemorrhage
2. Bleeding post-circumcision
3. Prolonged oozing from heel prick and venepuncture sites
What is the management for haemophilia A and B?
Haemophilia A: Recombinant FVIII concentrate
Haemophilia B: Recombinant FIX concentrate
-given by prompt iv infusion whenever there is bleeding
Phrophylatic FVIII to all children with severe Haemophilia A to reduce risk of chronic joint damage from the age of 2-3
What level of recombinant FVIII and FIX are given to treat a bleed (2)?
Depends on site and nature of the bleed.
1. For minor and simple bleeds: raising circulating level to 30% of normal
2. Major or life-threatening: raising circulating level to 100% and then maintained at 30-50% for up to 2 weeks
What medications must be avoided in Haemophilia (3)?
1. Intramuscular injections
What are the broad categories of bleeding disorders and examples of each?
3. Vit K deficiency
4. Liver disease
What is thrombocytopenia?
A platelet count of less than 150 x10^9/L
What are the 3 severity levels of platelet count? What is the risk of bleeding with each?
Severe: <20 x 10^9/L = risk of spontaneous bleeds
Moderate: 20-50 x 10^9/L = risk of excess bleeds during operations or trauma but low risk of spontaneous bleeds
Mild: 50-150 x 10^9/L = low risk of bleeding unless major operation or severe trauma
What are the clinical features of thrombocytopenia (5)?
4. Mucosal bleeding (epistaxis, bleeding from gums when brushing teeth)
5. Major haemorrhage (less common)
-Severe GI haemorrhage
What is immune thrombocytopenia (ITP)? What is it caused by?
The most common cause of thrombocytopenia in childhood.
Caused by destruction of circulating platelets by antiplatelet IgG autoantibodies
At what age do children usually present with ITP?
Between 2-10 years
What usually triggers the onset of ITP?
Usually occurs 1-2 weeks after a viral infection.
How long is the history of symptoms for ITP usually?
Short history of days or weeks
How do children with ITP present (4)?
What feature is uncommon?
3. and/or superficial bruising
4. Epistaxis and mucosal bleeding can occur
Profuse bleeding is uncommon
How is ITP diagnosed? What conditions need to be excluded (4)?
Diagnosis of exclusion - consider Hx, clinical features, FBC and blood film. Bone marrow exam if there are suspicious clinical features (if they have taken steroids as it can mask ALL)
1. Congenital causes e.g. Wiskott-Aldrich
2. Acute leukaemia (ALL)
3. Aplastic anaemia
What is the disease course for ITP?
It is acute, benign and self-limiting.
Usually remits spontaneously within 6-8 weeks
Where are children with ITP managed?
Most can be managed at home
How are children with acute ITP managed?
1. Minor cases
2. Major bleed/recurrent minor bleeds
3. Life-threatening haemorrhage
1. Most don't need therapy
2.Oral prednisolone, iv anti-D or iv immunoglobulin
3. Platelet transfusions
Immediate 24h access to hospital treatment for everyone. Child needs to avoid trauma and contact sports while platelet counts are low.
What is chronic ITP and how common is it?
In 20% of children, the platelet count remains low 6 months after diagnosis
What is the treatment for chronic ITP?
1. Most children
2. Chronic persistent bleeding that affects daily life
1. Supportive treatment
2. Rituximab - a monoclonal antibody directed against B lymphocytes
What is disseminated intravascular coagulation (DIC)?
A disorder characterised by coagulation pathway activation leading to diffuse fibrin deposition in the microvasculature and consumption of coagulation factors and platelets. Can be acute or chronic
What are the most common triggers of activation of coagulation in DIC (2)?
Shock due to circulatory collapse
What are the clinical features of DIC (3)?
What advice would you offer children with low platelet counts?
Avoid trauma and contact sports while platelet levels are low
In which group of patients with chronic ITP are offered splenectomy?
Those who have failed drug therapy