W17 60 leukaemias, lymphomas and bone marrow disorders Flashcards
What are some differential diagnoses of gingival hypertrophy?
Acute or chronic infections
Medications: phenytoin, ciclosporin, calcium channel blockers
Acute myeloid leukaemia
What is acute leukaemia?
A disorder of haematopoietic stem cells resulting in the rapid accumulation of clonal IMMATURE precursors in the bone marrow. An acute life threatening condition.
Is leukaemia associated with a high white cell count?
Not always, very often in acute leukaemia, all of the white cells are trapped in the bone marrow as immature precursors and people often present with a pancytopenia rather than a leucocytosis.
What is pancytopenia?
Having low levels of all 3 blood counts - WBCs, RBCs and platelets
What is leucocytosis?
A high white blood cell count
What are the 2 types of acute leukaemia?
Acute myeloid leukaemia (AML) - most common in adults
Acute lymphoblastic leukaemia (ALL) - most common in treatment
When do you need to treat acute leukaemias?
Requires treatment within hours/days of diagnosis - risk of death from bleeding/infection if delay.
What is the presentation of acute leukaemia?
Marrow failure - so anaemia, leukopenia, thrombocytopenia
Hyperviscosity due to leucocytosis - so headaches, breathlessness, visual blurring, confusion
Leukaemic infiltration (of malignant immature cells)
What can marrow failure in acute leukaemia cause?
Anaemia: fatigue, SOB, headaches, palpitations. Can result in end organ failure so MI and stroke.
Leukopenia: infections, mouth ulcers
Thrombocytopenia: purpura, bleeding, bruising
What does hyperviscosity due to leucocytosis in acute leukaemia cause?
Hyperviscosity due to leucocytosis means blood flow is slowed by the increase viscosity due to the presence of an excess number of both large and sticky WBCs.
Causes headaches, breathlessness, visual blurring, confusion
What does leukaemic infiltration (of malignant immature cells) in acute leukaemia cause?
AML can cause gingival hypertrophy
Skin lesions ‘chloromas’
Hepatosplenomegaly
What are key diagnostic investigations for assessment of leukaemias?
Clinical assessment
Full blood count
Blood film
Bone marrow assessment
What abnormal factor is seen in a full blood count in acute leukaemias? (PG588 DATA)
WBC is larger than the sum of all the parts beneath it, seen in acute leukaemias because the immature cells are not routinely reported. Blast cells not there and often make up the difference between the total of mature cells and total white cell count given.
What is haematopoiesis?
Production of blood cells. They have differential processes.
What are the different groups that come from multipotent stem cells to make each individual blood cell? (DIAGRAM PG588)
Common myeloid progenitor - megakaryoblasts-promegakaryoblast-megakaryocyte—>platelets; proerythroblasts-erythroblasts-reticulocyte—>RBCs; myloblasts—>basophils, neutrophils, eosinophils, macrophages; mast cells
Common lymphoid progenitor - lymphoblasts- T and B lymphocytes- plasma cells
What are the most numerous granulocyte?
Neutrophils are more numerous than basophils and eosinophils
What do monocytes end up as?
Macrophages that take up residence and present antigens through the tissues
What are the different types of leukocytosis (raised white cell count)?
Neutrophilia/monocytosis
Eosinophilia/basophilia
Lymphocytosis
What is neutrophilia/monocytosis and when does it occur?
Raised counts of neutrophils and monocytes
Usually raised due to a bacterial infection or inflammation
Neutrophilia can also come with raised steroid use
What is eosinophilia/basophilia and when does it occur?
Usually raised in allergy, parasitic infections
Eosinophilia also associated with a number of inflammatory and autoimmune diseases as well as drug side effects
What is Lymphocytosis and when does it occur?
Increased lymphocyte count
Usually raised due to viral infections or inflammation
Also can be seen in a number of lymphoproliferative diseases
What is neutropenia?
Low neutrophil count
What might happen in neutropenia and what should you do?
If the neutrophil count is low, life-threatening infection may develop rapidly - the presence of fever is a ‘medical emergency’ - needs immediate treatment with antibiotics.
What is febrile neutropenia?
Evidence of infection but low neutrophil count
A low neutrophil count should always prompt assessment of the cause, particularly if:
It is associated with symptoms
There are other cytopenias eg pancytopenia
It is persistently low
Should you perform dental procedures whilst patients are neutropenic?
It may be dangerous to perform dental procedures while patients are neutropenic - ideally avoid (especially in a time when the causes are known or there is expected to be a recovery of the neutrophil count)
What are some common causes of neutropenia?
Drugs - methotrexate, azathioprine, chemotherapy (commonly drugs used to treat autoimmune disease or prevent organ transplant rejection)
Viral infection, including HIV. (neutropenia = secondary to infection not a cause of infection)
B12/folate deficiency
What are some less common but still important causes of neutropenia?
Alcohol
Ethnicity
Hypersplenism
Bone marrow failure
Leukaemia
What is the spleen?
A site of a lot of haematopoietic stem cells.
A large spleen means a lot of blood cells will pool in the spleen, leading to a low neutrophil count, as well as low platelet count and anaemia in some patients.
In a blood film, what are blast cells like and what are they indicative of? (Pg590)
Blast cells have a very large nuclei, not much cytoplasm.
Usually resident in the bone marrow in very small numbers. Seeing them out in peripheral blood in a FBC is grossly abnormal and highly suspicious of acute leukaemia.
