Haem/Onc Flashcards
causes of neutropenia
viral HIV Epstein-Barr virus hepatitis drugs cytotoxics carbimazole clozapine benign ethnic neutropaenia common in people of black African and Afro-Caribbean ethnicity requires no treatment haematological malignancy myelodysplastic malignancies aplastic anemia rheumatological conditions systemic lupus erythematosus: mechanisms include circulating antineutrophil antibodies rheumatoid arthritis: e.g. hypersplenism as in Felty's syndrome severe sepsis haemodialysis
indication for treatment in CLL
progressive marrow failure: the development or worsening of anaemia and/or thrombocytopenia
massive (>10 cm) or progressive lymphadenopathy
massive (>6 cm) or progressive splenomegaly
progressive lymphocytosis: > 50% increase over 2 months or lymphocyte doubling time < 6 months
systemic symptoms: weight loss > 10% in previous 6 months, fever >38ºC for > 2 weeks, extreme fatigue, night sweats
autoimmune cytopaenias e.g. ITP
CLL management
patients who have no indications for treatment are monitored with regular blood counts
fludarabine, cyclophosphamide and rituximab (FCR) has now emerged as the initial treatment of choice for the majority of patients
ibrutinib may be used in patients who have failed a previous therapy
methaemoglobinaemia causes
Congenital causes
haemoglobin chain variants: HbM, HbH
NADH methaemoglobin reductase deficiency
Acquired causes
drugs: sulphonamides, nitrates (including recreational nitrates e.g. amyl nitrite ‘poppers’), dapsone, sodium nitroprusside, primaquine
chemicals: aniline dyes
methaemoglobinuria management
NADH - methaemoglobinaemia reductase deficiency: ascorbic acid
IV methylthioninium chloride (methylene blue) if acquired
most common cause of thrombophilia
factor V Leiden (activated protein C resistance)
prothrombin gene mutation (second most cause)
deficiencies of naturally occuring anticoagulants
antithrombin III deficiency
protein C deficiency
protein S deficiency
examples of sickle cell crisis
thrombotic, 'painful crises' sequestration acute chest syndrome aplastic haemolytic
what is thrombotic crisis?
also known as painful crises or vaso-occlusive crises
precipitated by infection, dehydration, deoxygenation
painful vaso-occlusive crises should be diagnosed clinically - there isn’t one test that can confirm them although tests may be done to exclude other complications
infarcts occur in various organs including the bones (e.g. avascular necrosis of hip, hand-foot syndrome in children, lungs, spleen and brain
what is sequestration crisis?
sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
what is acute chest syndrome?
dyspnoea, chest pain, pulmonary infiltrates, low pO2
the most common cause of death after childhood
what is aplastic crisis?
caused by infection with parvovirus
sudden fall in haemoglobin
what is haemolytic crisis?
rare
fall in haemoglobin due an increased rate of haemolysis
CLL features
often none: may be picked up by an incidental finding of lymphocytosis
constitutional: anorexia, weight loss
bleeding, infections
lymphadenopathy more marked than chronic myeloid leukaemia
CLL pathophysiology
a monoclonal proliferation of well-differentiated lymphocytes which are almost always B-cells (99%). It is the most common form of leukaemia seen in adults.
CLL investigations
full blood count:
lymphocytosis
anaemia
blood film: smudge cells (also known as smear cells)
immunophenotyping is the key investigation
ITP management
Emergency treatment: life-threatening or organ threatening bleeding Platelet transfusion, IV methylprednisolone and intravenous immunoglobulin
Platelet count >30*109/L Observation
Platelet count <30*109/L Oral prednisolone
ITP pathophysiology
Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex.
Children with ITP usually have an acute thrombocytopenia that may follow infection or vaccination. In contract, adults tend to have a more chronic condition.
ITP presentation
may be detected incidentally following routine bloods
symptomatic patients may present with
petichae, purpura
bleeding (e.g. epistaxis)
catastrophic bleeding (e.g. intracranial) is not a common presentation
what is Evan’s syndrome>
ITP in association with autoimmune haemolytic anaemia (AIHA)
paroxysmal nocturnal haemoglobinuria pathophysiology
an acquired disorder leading to haemolysis (mainly intravascular) of haematological cells. It is thought to be caused by increased sensitivity of cell membranes to complement (see below) due to a lack of glycoprotein glycosyl-phosphatidylinositol (GPI). Patients are more prone to venous thrombosis
Pathophysiology
GPI can be thought of as an anchor which attaches surface proteins to the cell membrane
complement-regulating surface proteins, e.g. decay-accelerating factor (DAF), are not properly bound to the cell membrane due a lack of GPI
thrombosis is thought to be caused by a lack of CD59 on platelet membranes predisposing to platelet aggregation
paroxysmal nocturnal haemoglobinuria features
haemolytic anaemia
red blood cells, white blood cells, platelets or stem cells may be affected therefore pancytopaenia may be present
haemoglobinuria: classically dark-coloured urine in the morning (although has been shown to occur throughout the day)
thrombosis e.g. Budd-Chiari syndrome
aplastic anaemia may develop in some patients
paroxysmal nocturnal haemoglobinuria diagnosis
flow cytometry of blood to detect low levels of CD59 and CD55 has now replaced Ham’s test as the gold standard investigation in PNH
Ham’s test: acid-induced haemolysis (normal red cells would not)
paroxysmal nocturnal haemoglobinuria management
blood product replacement
anticoagulation
eculizumab, a monoclonal antibody directed against terminal protein C5, is currently being trialled and is showing promise in reducing intravascular haemolysis
stem cell transplantation
hyposplenism on blood film
target cells Howell-Jolly bodies Pappenheimer bodies siderotic granules acanthocytes
IDA blood film
target cells
‘pencil’ poikilocytes
if combined with B12/folate deficiency a ‘dimorphic’ film occurs with mixed microcytic and macrocytic cells
myelofibrosis blood film
‘tear-drop’ poikilocytes
intravascular haemolysis on blood film
schistocytes
megaloblastic anaemia on blood film
hypersegmented neutrophils
what are the porphyrias?
abnormality in enzymes responsible for the biosynthesis of haem
results in overproduction of intermediate compounds (porphyrins)
may be acute or non-acute
Acute intermittent porphyria
autosomal dominant
defect in porphobilinogen deaminase
female and 20-40 year olds more likely to be affected
typically present with abdominal symptoms, neuropsychiatric symptoms
hypertension and tachycardia common
urine turns deep red on standing
porphyria cutanea tarda
most common hepatic porphyria
defect in uroporphyrinogen decarboxylase
may be caused by hepatocyte damage e.g. alcohol, oestrogens
classically photosensitive rash with bullae, skin fragility on face and dorsal aspect of hands
urine: elevated uroporphyrinogen and pink fluorescence of urine under Wood’s lamp
manage with chloroquine
variegate porphyria
autosomal dominant defect in protoporphyrinogen oxidase photosensitive blistering rash abdominal and neurological symptoms more common in South Africans
categories of tumor markers
monoclonal antibodies against carbohydrate or glycoprotein tumour antigens
tumour antigens
enzymes (alkaline phosphatase, neurone specific enolase)
hormones (e.g. calcitonin, ADH)
monoclonal antibody tumor markers
CA 125 Ovarian cancer
CA 19-9 Pancreatic cancer
CA 15-3 Breast cancer
tumor antigen markers
Prostate specific antigen (PSA) Prostatic carcinoma
Alpha-feto protein (AFP) Hepatocellular carcinoma, teratoma
Carcinoembryonic antigen (CEA) Colorectal cancer
S-100 Melanoma, schwannomas
Bombesin Small cell lung carcinoma, gastric cancer, neuroblastoma
ECOG score
0 Fully active, able to carry on all pre-disease performance without restriction
1 Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature, e.g., light house work, office work
2 Ambulatory and capable of all selfcare but unable to carry out any work activities; up and about more than 50% of waking hours
3 Capable of only limited selfcare; confined to bed or chair more than 50% of waking hours
4 Completely disabled; cannot carry on any selfcare; totally confined to bed or chair
5 Dead
common neutrophil disorders
- chronic granulomatous disease
- chediak-higashi syndrome
- leukocyte adhesion deficiency
what is chronic granulomatous disease?
Lack of NADPH oxidase reduces ability of phagocytes to produce reactive oxygen species
Causes recurrent pneumonias and abscesses, particularly due to catalase-positive bacteria (e.g. Staphylococcus aureus and fungi (e.g. Aspergillus)
Negative nitroblue-tetrazolium test
Abnormal dihydrorhodamine flow cytometry test
What is Chediak-higashi syndrome?
Microtubule polymerization defect which leads to a decrease in phagocytosis Affected children have ‘partial albinism’ and peripheral neuropathy. Recurrent bacterial infections are seen
Giant granules in neutrophils and platelets
what is leukocyte adhesion deficiency?
Defect of LFA-1 integrin (CD18) protein on neutrophils Recurrent bacterial infections.
Delay in umbilical cord sloughing may be seen
Absence of neutrophils/pus at sites of infection
what are the common B-cell disorders?
- Common variable immunodeficiency
- Bruxton’s congenital agammaglobulinaemia
- selective IgA deficiency
what is the common T-cell disorder?
DiGeorge syndrome 22q11.2 deletion, failure to develop 3rd and 4th pharyngeal pouches Common features include congenital heart disease (e.g. tetralogy of Fallot), learning difficulties, hypocalcaemia, recurrent viral/fungal diseases, cleft palate
what is common variable immunodeficiency?
Many varying causes Hypogammaglobulinemia is seen. May predispose to autoimmune disorders and lymphona
what is Bruton’s congenital agammaglobulinaemia?
Defect in Bruton’s tyrosine kinase (BTK) gene that leads to a severe block in B cell development X-linked recessive. Recurrent bacterial infections are seen
Absence of B-cells with reduced immunoglogulins of all classes
what is selective IgA deficiency?
Maturation defect in B cells Most common primary antibody deficiency. Recurrent sinus and respiratory infections
Associated with coeliac disease and may cause false negative coeliac antibody screen
Severe reactions to blood transfusions may occur (anti-IgA antibodies → analphylaxis)
combine B and T cell disorders
- Severe combined immunodeficiency
- Ataxic telangiectasia
- Wiskott-Aldrich syndrome
- Hyper IgM Syndromes
what is Severe combined immunodeficiency?
Many varying causes. Most common (X-linked) due to defect in the common gamma chain, a protein used in the receptors for IL-2 and other interleukins. Other causes include adenosine deaminase deficiency Recurrent infections due to viruses, bacteria and fungi.
Reduced T-cell receptor excision circles
Stem cell transplantation may be successful
what is ataxic telangiectasia?
Defect in DNA repair enzymes Autosomal recessive. Features include cerebellar ataxia, telangiectasia (spider angiomas), recurrent chest infections and 10% risk of developing malignancy, lymphoma or leukaemia
what is Wiskott-Aldrich syndrome?
Defect in WASP gene X-linked recessive. Features include recurrent bacterial infections, eczema, thrombocytopaenia.
Low IgM levels
Increased risk of autoimmune disorders and malignancy
what is hyper IgM ?
Mutations in the CD40 gene Infection/Pneumocystis pneumonia, hepatitis, diarrhoea
what is Waldenstom’s macroglobulinaemia?
Waldenstrom’s macroglobulinaemia is an uncommon condition seen in older men. It is a lymphoplasmacytoid malignancy characterised by the secretion of a monoclonal IgM paraprotein
Features monoclonal IgM paraproteinaemia systemic upset: weight loss, lethargy hyperviscosity syndrome e.g. visual disturbance the pentameric configuration of IgM increases serum viscosity hepatosplenomegaly lymphadenopathy cryoglobulinaemia e.g. Raynaud's
What is the most common inherited bleeding disorder?
Von Willebrand’s disease
Autosomal dominant
types of von willebrand disease
type 1: partial reduction in vWF (80% of patients)
type 2*: abnormal form of vWF
type 3**: total lack of vWF (autosomal recessive)
role of von willebrand factor
large glycoprotein which forms massive multimers up to 1,000,000 Da in size
promotes platelet adhesion to damaged endothelium
carrier molecule for factor VIII
investigations von willebrand disease
prolonged bleeding time
APTT may be prolonged
factor VIII levels may be moderately reduced
defective platelet aggregation with ristocetin
Mx of VWD
tranexamic acid for mild bleeding
desmopressin (DDAVP): raises levels of vWF by inducing release of vWF from Weibel-Palade bodies in endothelial cells
factor VIII concentrate
follicular lymphoma translocation
t(14;18)
CML translocation
t(9;22)
Burkitt lymphoma translocation
t(8;14)
mantle cell lymphoma translocation
t(11;14)
acute promyelocytic leukaemia translocation
t(15;17)
which is more common, hodgkin’s or non-hodgkins?
non-hodgkin’s
non hodgkin’s lymphoma risk factors
Elderly
Caucasians
History of viral infection (specifically Epstein-Barr virus)
Family history
Certain chemical agents (pesticides, solvents)
History of chemotherapy or radiotherapy
Immunodeficiency (transplant, HIV, diabetes mellitus)
Autoimmune disease (SLE, Sjogren’s, coeliac disease)
non hodgkin’s lymphoma symptoms
Painless lymphadenopathy (non-tender, rubbery, asymmetrical) Constitutional/B symptoms (fever, weight loss, night sweats, lethargy) Extranodal Disease - gastric (dyspepsia, dysphagia, weight loss, abdominal pain), bone marrow (pancytopenia, bone pain), lungs, skin, central nervous system (nerve palsies)
differentiate non-hodkins from hodgkins lymphoma
Lymphadenopathy in Hodgkin’s lymphoma can experience alcohol-induced pain in the node
‘B’ symptoms typically occur earlier in Hodgkin’s lymphoma and later in non-Hodgkin’s lymphoma
Extra-nodal disease is much more common in non-Hodgkin’s lymphoma than in Hodgkin’s lymphoma
non-hodgkins lymphoma investigations
Excisional node biopsy is the diagnostic investigation of choice (certain subtypes will have a classical appearance on biopsy such as Burkitt’s lymphoma having a ‘starry sky’ appearance)
CT chest, abdomen and pelvis (to assess staging)
HIV test (often performed as this is a risk factor for non-Hodgkin’s lymphoma)
FBC and blood film (patient may have a normocytic anaemia and can help rule out other haematological malignancy such as leukaemia)
ESR (useful as a prognostic indicator)
LDH (a marker of cell turnover, useful as a prognostic indicator)
Other investigations can be ordered as the clinical picture indicates (LFT’s if liver metastasis suspected, PET CT or bone marrow biopsy to look for bone involvement, LP if neurological symptoms)
non-hodgkins lymphoma stageing
The most common staging system used for non-Hodgkin’s lymphoma is the Ann Arbor system.
Stage 1 - One node affected
Stage 2 - More than one node affected on the same side of the diaphragm
Stage 3 - Nodes affected on both sides of the diaphragm
Stage 4 - Extra-nodal involvement e.g. Spleen, bone marrow or CNS
The stage is combined with the letter A or B to indicate the presence of ‘B’ symptoms. With the letter A indicating no B symptoms present and B indicating any of the beta symptoms present. For example, a patient with a single node affected and no ‘B’ symptoms would be stage 1A.
non-hodgkins lymphoma management
Management is dependent on the specific sub-type of non-Hodgkin’s lymphoma and will typically take the form of watchful waiting, chemotherapy or radiotherapy.
All patients will receive flu/pneumococcal vaccines
Patients with neutropenia may require antibiotic prophylaxis
non-hodgkins lymphoma complications
Bone marrow infiltration causing anaemia, neutropenia or thrombocytopenia
Superior vena cava obstruction
Metastasis
Spinal cord compression
Complications related to treatment e.g. Side effects of chemotherapy
malignancy associated with EBV
Hodgkin’s and Burkitt’s lymphoma, nasopharyngeal carcinoma
malignancy associated with HTLV-1
adult T-cell leukaemia/lymphoma
malignancy associated with HIV-1
High-grade B-cell lymphoma
malignancy associated with H.pylori
gastric lymphoma (MALT)
malignancy associated with protozoa
malaria- Burkitt’s lymphoma
multiple myeloma features
C - hypercalcaemia
R - renal insufficiency (suggested by the U&Es and complicated by the recurrent UTIs - patients are susceptible to infections as the production of antibodies by normal plasma cells is impaired)
A - this patient is short of breath due to her anaemia (and the FBC shows evidence of pancytopenia - typically due to plasma cells infiltrating the bone marrow)
B - bone pain (albeit subtle in the form of a vague history of lower back pain)
myeloma investigations
monoclonal proteins (usually IgG or IgA) in the serum and urine (Bence Jones proteins) increased plasma cells in the bone marrow historically a skeletal survey has been done to look for bone lesions. However, whole-body MRI is increasingly used and is now recommended in the 2016 NICE guidelines X-rays: 'rain-drop skull' (likened to the pattern rain forms after hitting a surface and splashing, where it leaves a random pattern of dark spots). Note that a very similar, but subtly different finding is found in primary hyperparathyroidism - 'pepperpot skull'
myeloma criteria
Major criteria
Plasmacytoma (as demonstrated on evaluation of biopsy specimen)
30% plasma cells in a bone marrow sample
Elevated levels of M protein in the blood or urine
Minor criteria
10% to 30% plasma cells in a bone marrow sample.
Minor elevations in the level of M protein in the blood or urine.
Osteolytic lesions (as demonstrated on imaging studies).
Low levels of antibodies (not produced by the cancer cells) in the blood.
what causes hypercalcaemia in myeloma?
primary factor: due primarily to increased osteoclastic bone resorption caused by local cytokines (e.g. IL-1, tumour necrosis factor) released by the myeloma cells
much less common contributing factors: impaired renal function, increased renal tubular calcium reabsorption and elevated PTH-rP levels
causes of thrombocytosis
reactive: platelets are an acute phase reactant - platelet count can increase in response to stress such as a severe infection, surgery. Iron deficiency anaemia can also cause a reactive thrombocytosis
malignancy
essential thrombocytosis (see below), or as part of another myeloproliferative disorder such as chronic myeloid leukaemia or polycythaemia rubra vera
hyposplenism
what is essential thrombocytosis?
Essential thrombocytosis is one of the myeloproliferative disorders which overlaps with chronic myeloid leukaemia, polycythaemia rubra vera and myelofibrosis. Megakaryocyte proliferation results in an overproduction of platelets.
Features
platelet count > 600 * 109/l
both thrombosis (venous or arterial) and haemorrhage can be seen
a characteristic symptom is a burning sensation in the hands
a JAK2 mutation is found in around 50% of patients