Haematology Flashcards
What is acute leukemia?
The rapid proliferation of immature blood cells (blast).
>20% blast in BM for diagnosis
Highest growth fraction
HSC is already lymphoid or myeloid committed, hence AML OR ALL
What is chronic leukemia?
Proliferation and excessive build-up of relatively mature blood cells over a longer timeframe.
Apparently mature, but not normal.
Usually lost of apoptotic mechanisms.
Define leukemogenesis.
Gene mutations in bone marrow progenitor cells underlie the malignant transformation of normal haemopoietic cells.
Outline the concept of an oncogene.
They are mutations in a pro-oncogene -required cell growth.
Oncogenes promote cell growth, uncontrollably, either by chemical messengers or signal conduction.
Expression in inappropriate cell types, activating the expression of the gene under inappropriate conditions, changing the localisation of the protein product, making the protein unresponsive to cell signaling cascade regulation etc.
Production and maintenance of malignancy.
Outline the concept of oncogenesis.
Carcinogenesis- normal cells to cancerous cells.
Cellular, genetic, and epigenetic levels
Somatic mutation- disrupts the regulated cell division and cell death in the body.
Cancer-promoting genes suppress Tumour Suppressor genes.
How does dysregulation lead to neoplasms?
Cancerous tissue proliferates and forms an abnormal growth of tissue called neoplasms.
These cells undergo metaplasia or dysplasia.
Why are malignancies referred to as clonal disorders?
That all malignant cells are descendants of one early precursor cell that underwent a malignant transformation.
Describe APL.
RARA gene (which is important for neutrophil production) translocates with PML and disrupts normal myeloid differentiation. Causes DIC due to the release of pro-coagulants.
Do a FISH testing
(15,17)
Describe the complication of Bone Marrow failure.
Systemic Anaemia- due to reduced RBC production and blood loss. More susceptible to infections and harder to fight them off. Stroke.
Thrombocytopenia- Excessive bleeding and bruising.
Neutropenia- cause severe infections that can lead to neutropenic fevers
Describe what would be seen on a full blood count, that indicates the possibility of leukemia.
WBC elevated- immune response to cancer
however the automated analyser can pick up blasts as WBC. WBC can also stay low- have not entered circulation as yet.
Blood films can give a hint of AML or ALL
Normocytic anaemia
thrombocytopenia
The Diagnosis is confirmed by a bone marrow biopsy.
Describe the morphology of AML.
Large blasts
Primitive nuclei
Cytoplasmic granules
Auer rods
from a HSC that is myeloid committed
Describe the morphology of ALL.
Scanty cytoplasm
Primitive nuclei
No cytoplasm granules
No Auer rods
From HSC that is lymphoid committed
What is the importance of a bone marrow biopsy?
To confirm an acute leukemia diagnosis.
To assess the blast morphology.
Used for other special tests to subclassify
Explain the rationale behind immunophenotyping.
The best method to use when sub-classifying acute leukemia.
It analyses cellular Antigens, surface, cytoplasm, etc.
Determines lineage
Describe leukostasis.
Hyperviscosity due increase in WBC
AML and CML
Decreased tissue perfusion, can lead to pulmonary and neurological symptoms.
Do not give RBC.
What are the side effects of chemotherapy?
Short-term effects include:
Bone marrow suppression and pancytopenia.
Risk for severe infection due to neutropenia and concurrent steroid use.
Nausea and vomiting (very common)
Diarrhoea
Tumour lysis syndrome
Mouth ulcers
Teratogenicity
Autonomic neuropathy (paraesthesia in hands and feet)
Differentiation syndrome in APL
Reactivation of latent viral hepatitis.
Long-term side effects include:
Risk of secondary malignancies (solid tumours or haematological malignancies, especially if patient is treated with both chemotherapy and radiotherapy.
Reduced fertility.
Cardiac failure (some drugs).
Osteopenia/osteoporosis.
Hypothyroidism
Growth restriction in children