Miscellaneous Haematology Flashcards
What are myeloproliferative disorders?
It is the name of a group of conditions which cause platelets, white blood cells, and red blood cells, to grow abnormally within the bone marrow.
What are the different types of myeloproliferative disorders?
Polycythaemia Rubra Vera: BM produces too many RBCs
Essential thrombocytosis: BM produce too many platelets
Myelofibrosis: production of large numbers of immature cells, these cells cause fibrosis of the BM. Essentially is a type of bone marrow cancer.
Polycythaemia rubra vera and essential thrombocytosis can both progress to cause myelofibrosis.
How do myeloproliferative disorders present?
Often in older people (older than 50) as much more common with age.
Often asymptomatic and presentation is incidental findings.
A common sign myeloproliferative disorders is splenomegaly as it takes over over the erythropoietic role.
How might PRV present?
Often asymptomatic
If present symptoms include:
- Fatigue and malaise.
- Purpura
- Headache and problems with vision
- High blood pressure
- A third present with thrombosis (usually arterial but some venous)
How might essential thrombocytosis present?
Malaise and fatigue.
Fever.
Neuro:
Headache
Burning pain and a dusky appearance of extremities
Arterial or venous clots
Bleeding: usually GI
How does myelofibrosis present?
The clinical features of MF are variable and include:
- progressive anaemia, leukopenia or leukocytosis
- thrombocytopenia or thrombocytosis
- multi-organ extramedullary haemopoiesis causing hepatomegaly and symptomatic splenomegaly.
In advanced disease there are severe constitutional symptoms:
-general malaise/weight loss/night sweats and low-grade fever
Also symptoms of massive splenomegaly
-pain/early satiety/splenic infarction/portal hypertension and dyspnoea)
There is also progressive marrow failure which can cause severe anaemia and bleeding.
It may also transform to a more aggressive form of leukaemia.
What is aplastic anaemia?
It is a failure of haemopoesis causing pancytopenia and hypocellular bone marrow.
Clinically how does aplastic anaemia present?
Can present abruptly or insidiously over weeks to months.
Patients with aplastic anaemia most commonly present with symptoms of anaemia:
Pallor, headache, palpitations, dyspneoa, and fatigue
And with symptoms of thrombocytopenia: skin or mucosal haemorrhage, visual disturbance due to retinal haemorrhage and petechial rashes.
Note there should be splenomegaly or lymphadenopathy in the absence of infection
What are the potential causes of aplastic anaemia?
Congenital or acquired. (congenital is very rare)
Acquired: Idiopathic Infection (EBV, HIV, Hepatitis, mycobacteria) Radiation Drug reactions Graft vs host disease
What is the laboratory diagnosis for aplastic anaemia?
To define aplastic anaemia based on FBC and bone marrow findings, at least two of the following must be present:
- Haemoglobin <10 g/dL
- Platelet count < 50 x 109/L
- Neutrophil count <1.5 x 109/L
BM cellularity is used to determine the severity.
How should patients with aplastic anaemia be managed?
Treatment should be based on the degree of cytopenia, not the marrow cellularity. Patients with asymptomatic cytopenias probably need no treatment.
In severe disease:
-BM cell transplantation is 1st line if a compatible match can be found from a sibling.
OR
-Immunosuppressant therapy involving antithymocyte globulin or antilymphocyte globulin: + ciclpsporin.
Supportive care should be given with transfusions depending on blood results.
Neutrophil count needs close monitoring if less than 0.5 needs hospitalisation and prophylaxis with antibiotics and antifungals. Patients are susceptible to overwhelming aspergillus sepsis.
Describe the management of a patient with a splenectomy?
Full immunisation ideally 2 weeks before the splenectomy then boosters should be given at 5 yearly intervals.
Lifelong prophylactic antibiotics:
Phenoxymethylpenicillin or amoxolcillin
If penicillin allergic: macrolides
Splenectomised patients are at particular risk of pneumococcal infections.
