Medicine- haem/ onc Flashcards
Best initial test for ?leukemia
CBC with smear showing blast cells
Auer rods are characteriestic of what?
AML subtype M3
Most accurate test for leukemia
BM biopsy with flow cytometry
Who tends to get CLL?
Older people, M>F
What are the characteristic cells of CLL?
Smudge cells (fragile leukemia cells crushed by the slide)
What are Reed Sternberg cells associated with?
Hodgkin lymphoma
What is this?
Dense metaphyseal lines which are associated with lead poisoning
Lead limits in blood
The Centers for Disease Control (US) has set the upper limit for blood lead for adults at 10 µg/dl (10 µg/100 g) and for children at 5 µg/d
Signs of lead poisoning on blood smear
Patients with lead poisoning will often show basophilic stippling (it’s not unique to lead poisoning though). Microcytosis and hypochromia may be present, and reticulocyte counts may be elevated
What does LMWH affect in the coagulation pathway and how do you monitor it?
LMWH does not require routine monitoring because it exerts its effect on factor Xa in the coagulation pathway, which is not tracked by the PT/INR or aPTT
When is Haemoglobin F seen?
Haemoglobin F dominates until about 6 weeks of age
Pattern of inheritance sickle cell anemia
Autosomal recessive
The genetic defect in sickle cell anemia
Chromosome 11
The gene defect is a single nucleotide mutation (GAG codon changing to GTG) of the β-globin gene, which results in glutamic acid (E/Glu) being substituted by valine (V/Val) at position 6 (E6V substitution). Haemoglobin S with this mutation is referred to as HbS, as opposed to the normal adult HbA.
(Note that sickle cell anemia is specific to β-globin)
Diagnosis of sickle cell anemia
- Hb electrophoresis
- Confirm with high-performance liquid chromatography
Over the course of two months, a 62-year-old man developed numbness and a “pins and needles” sensation in his hands, had trouble walking, experienced severe joint pain, began turning yellow, and became progressively short of breath
What’s the most likely diagnosis?
Vitamin B12 deficiency
Characteristics of pernicious anemia
Anemia with bone marrow promegaloblastosis (megaloblastic anemia). Due to the inhibition of DNA synthesis (specifically purines + thymidine).
Gastrointestinal symptoms: alteration in bowel motility, loss of bladder or bowel control.
Neurological symptoms: Sensory or motor (absent reflexes, diminished vibration or soft touch sensation), subacute combined degeneration of spinal cord, or seizures.
Deficiency symptoms in children include: developmental delay, regression, irritability, involuntary movements and hypotonia.
What does this show?
Peripheral blood smear showing hypersegmented neutrophils, characteristic of megaloblastic anemia.
What does megaloblastic anemia result from?
Inhibition of DNA synthesis during red blood cell production.
When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis (M) stage. This leads to continuing cell growth without division, which presents as macrocytosis.
What is the pathological state of megaloblastosis is characterized by?
The pathological state of megaloblastosis is characterized by many large immature and dysfunctional red blood cells (megaloblasts) in the bone marrow and also by hypersegmented neutrophils (defined as the presence of neutrophils with six or more lobes or the presence of more than 3% of neutrophils with at least five lobes).
These hypersegmented neutrophils can be detected in the peripheral blood (using a diagnostic smear of a blood sample).
Causes of Vitamin B12 deficiency
- Achlorhydria-induced malabsorption
- Deficient intake
- Deficient intrinsic factor- required for B12 absorption (pernicious anemia or gastrectomy)
- Coeliac disease
- Biological competition for vitamin B12 by diverticulosis, fistula, intestinal anastomosis, or infection by the marine parasite Diphyllobothrium latum (fish tapeworm)
- Selective vitamin B12 malabsorption (congenital—juvenile megaloblastic anemia 1—and drug-induced)
- Chronic pancreatitis
- Ileal resection and bypass
- Nitrous oxide anesthesia (usually requires repeated instances).