Haematological Cancers Flashcards
Leukaemia is cancer of a particular line of stem cells in the bone marrow, causing unregulated production of a specific type of blood cell.
The types of leukaemia can be classified depending on how rapidly they progress (chronic is slow and acute is fast) and the cell line that is affected (myeloid or lymphoid) to make four main types:
Acute myeloid leukaemia (rapidly progressing cancer of the myeloid cell line)
Acute lymphoblastic leukaemia (rapidly progressing cancer of the lymphoid cell line)
Chronic myeloid leukaemia (slowly progressing cancer of the myeloid cell line)
Chronic lymphocytic leukaemia (slowly progressing cancer of the lymphoid cell line)
What patient group is most affected by leukaemia?
Most types of leukaemia occur in patients over 60-70. The exception is acute lymphoblastic leukaemia, which most commonly affects children under five years.
the most common leukaemia in children and is associated with Down syndrome =
ALL
leukaemia associated with warm haemolytic anaemia, Richter’s transformation and smudge cells =
CLL
leukaemia with three phases, including a long chronic phase, and is associated with the Philadelphia chromosome =
CML
leukaemia that may result in a transformation from a myeloproliferative disorder and is associated with Auer rods =
AML
What is the pathophysiology of leukaemia?
A genetic mutation in one of the precursor cells in the bone marrow leads to excessive production of a single type of abnormal white blood cell.
The excessive production of a single type of cell can suppress the other cell lines, causing the underproduction of different cell types. This can result in pancytopenia, which is a combination of low red blood cells (anaemia), white blood cells (leukopenia) and platelets (thrombocytopenia).
How may leukaemia present?
Fatigue
Fever
Lymphadenopathy
Hepatosplenomegaly
Pallor due to anaemia
Petechiae or bruising due to thrombocytopenia
Abnormal bleeding
Failure to thrive (children)
One key presenting feature of leukaemia is bleeding under the skin due to thrombocytopenia. Bleeding under the skin causes non-blanching lesions.
These lesions are called different things based on the size of the lesions:
Petechiae are less than 3mm and caused by burst capillaries
Purpura are 3 – 10mm
Ecchymosis is larger than 1cm
The top differentials for a non-blanching rash caused by bleeding under the skin are:
Leukaemia
Meningococcal septicaemia
Vasculitis
Henoch-Schönlein purpura (HSP)
Immune thrombocytopenic purpura (ITP)
Thrombotic thrombocytopenic purpura (TTP)
Traumatic or mechanical (e.g., severe vomiting)
Non-accidental injury
How can leukaemia be diagnosed?
FBC within 48 hours
Lactate dehydrogenase (often raised in leukaemia but is a very non-specific marker)
A blood film
Bone marrow biopsy
CT and PET scans for staging
Outline the options for obtaining a bone marrow biopsy
usually taken from the iliac crest
involves a local anaesthetic and a specialist needle
The options are aspiration or trephine:
Bone marrow aspiration = taking a liquid sample of cells from within the bone marrow
Bone marrow trephine = solid core sample of the bone marrow, provides a better assessment of the cells and structure
What is the pathophysiology of ALL?
Acute lymphoblastic leukaemia (ALL) affects one of the lymphocyte precursor cells, causing acute proliferation of a single type of lymphocyte, usually B-lymphocytes. Excessive accumulation of these cells replaces the other cell types in the bone marrow, leading to pancytopenia.
ALL most often affects children under five but can also affect older adults. It is more common with Down’s syndrome.
What is the pathophysiology of CLL? How does it present?
Chronic lymphocytic leukaemia is where there is slow proliferation of a single type of well-differentiated lymphocyte, usually B-lymphocytes.
It usually affects adults over 60 years of age.
It is often asymptomatic but can present with infections, anaemia, bleeding and weight loss.
How can CLL be investigated?
FBC:
* lymphocytosis
* anaemia: due to bone marrow replacement or autoimmune hemolytic anaemia (AIHA)
* thrombocytopenia: either due to bone marrow replacement or ITP
blood film: smudge cells
immunophenotyping is the key investigation
Give 4 complications of CLL
anaemia
hypogammaglobulinaemia leading to recurrent infections
warm autoimmune haemolytic anaemia in 10-15% of patients
transformation to high-grade lymphoma (Richter’s transformation)
What is Richter’s transformation?
when leukaemia cells enter the lymph node and change into a high-grade, fast-growing non-Hodgkin’s lymphoma. Patients often become unwell very suddenly
How does Richter’s transformation present?
lymph node swelling
fever without infection
weight loss
night sweats
nausea
abdominal pain
What are smear or smudge cells on blood film?
ruptured white blood cells that occur while preparing the blood film when the cells are aged or fragile. They are particularly associated with chronic lymphocytic leukaemia.
What are the 3 phases of CML?
Chronic phase
Accelerated phase
Blast phase
The chronic phase is often asymptomatic, and patients are diagnosed after an incidental finding of a raised WCC - can last several years before progressing.
The accelerated phase occurs when the abnormal blast cells take up a high proportion (10-20%) of the bone marrow and blood cells. In the accelerated phase, patients are more symptomatic and develop anaemia, thrombocytopenia and immunodeficiency.
The blast phase follows the accelerated phase and involves an even higher proportion (over 20%) of blast cells in the blood. The blast phase has severe symptoms and pancytopenia and is often fatal.
How may CML present?
Presentation (60-70 years)
anaemia: lethargy
weight loss and sweating are common
splenomegaly → abdo discomfort
On investigation:
an increase in granulocytes at different stages of maturation +/- thrombocytosis
decreased leukocyte alkaline phosphatase
How may CML be managed?
imatinib is now considered first-line treatment
- inhibitor of the tyrosine kinase associated with the BCR-ABL defect, very high response rate in chronic phase CML
hydroxyurea
interferon-alpha
allogenic bone marrow transplant
When does AML commonly present?
It can present at any age but normally presents from middle age onwards.
It can be the result of a transformation from a myeloproliferative disorder, such as polycythaemia rubra vera or myelofibrosis.
What may be found on blood film and bone marrow biopsy in AML?
high proportion of blast cells
Auer rods in the cytoplasm of blast cells are a characteristic finding
Give some poor prognostic features in AML
> 60 years
20% blasts after first course of chemo
cytogenetics: deletions of chromosome 5 or 7
What targeted therapies can be used to treat leukaemia?
Tyrosine kinase inhibitors (e.g., imantinib)
Monoclonal antibodies (e.g., rituximab, which targets B-cells)
Give some complications of chemotherapy
Failure to treat cancer
Stunted growth and development in children
Infections due to immunosuppression
Neurotoxicity
Cardiotoxicity
Infertility
Secondary malignancy
Tumour lysis syndrome
Lymphoma is a type of cancer affecting the lymphocytes inside the lymphatic system. Cancerous cells proliferate inside the lymph nodes, causing the lymph nodes to become abnormally large (lymphadenopathy).
What are the 2 main types?
Hodgkin’s lymphoma (a specific disease)
Non-Hodgkin’s lymphoma (which includes all other types)
Hodgkin’s lymphoma is the most common specific type of lymphoma. It has a bimodal age distribution with peaks around 20-25 and 80 years.
Risk factors for Hodgkin’s lymphoma include:
HIV
Epstein-Barr virus
Autoimmune conditions, such as rheumatoid arthritis and sarcoidosis
Family history
Non-Hodgkin’s lymphoma includes many types. A few notable ones are:
Diffuse large B cell lymphoma typically presents as a rapidly growing painless mass in older patients
Burkitt lymphoma is particularly associated with Epstein-Barr virus and HIV
MALT lymphoma affects the mucosa-associated lymphoid tissue, usually around the stomach
Risk factors for non-Hodgkin’s lymphoma include:
HIV
Epstein-Barr virus
Helicobacter pylori (H. pylori) infection is associated with MALT lymphoma
Hepatitis B or C infection
Exposure to pesticides
Exposure to trichloroethylene (a chemical with a variety of industrial uses)
Family history
How may lymphoma present?
Lymphadenopathy
The enlarged lymph nodes might be in the neck, axilla or inguinal region. They are characteristically non-tender and feel firm or rubbery.
Patients with Hodgkin’s lymphoma may experience lymph node pain after drinking alcohol
B symptoms refer to systemic symptoms of lymphoma:
Fever
Weight loss
Night sweats