Welcome to nephroguy's page.
Contributor score: 5
To add to this: homozygous HS presents with hemolysis even in absence of stressors. this patient is only presenting with pale skin, and there are no schistocytes on the peripheral smear, so it's a heterozygous ankyrin mutation.
I wanted to pick hereditary spherocytosis but the mean corpuscular concentration was normal and I thought it was supposed to be elevated? Also, why are there so many RBCs that are way bigger than the spherocytes?
I'm assuming that the MCC is normal because the patient is heterozygous for HS. Not sure if this is correct, but that was my thought process
Are there any papers that explain the difference in expression of homozygous vs heterozygous HS?
I don't know if that matters as much, like the phenotype difference of homozygous or heterozygous for this question. Since you only need one allele to show this, play odds. Is he more likely to have AA or Aa. That was my thought process.
Also if you see spherocytes you'd be going for ankyrin right, not B-globin bc that should be target cells - regardless of MCHC.
as I remember AD are always heterzygous. Because homozygous are always lethal.
All of this is correct except its intravascular hemolysis, not extravascular. Also look for hemosiderinuria, hemoglobinuria and schistocytes on blood smear
Is not intravascular hemolysis, it is extrinsic hemolysis, specifically macroangiopathic hemolytic anemia. FA 2020 page 423.
This is actually BOTH intravascular hemolysis & extrinsic hemolysis.
Extrinsic = hemolysis that isn't caused by an internal defect of the RBCs, like an enzyme/membrane defect (in other words, it's hemolysis due to an external factor like a mechanical valve).
Intravascular = hemolysis that occurs within the blood vessels (RBCs get damaged as they pass through the valve). This is in contrast to extravascular hemolysis which describes hemolysis that occurs outside of the blood vessels (e.g. inside the spleen)
I believe so, FA 2018 pg 299
It is dissection "extra lumen in the media of the proximal aorta" = "a longitudinal intimal (tunica intima) tear with dissection of blood through the media of the aortic wall" ... answer is still hypertension
FA 2019: 301
First Aid says that aortic dissection causes widening of the mediastinum and is due to an intimal tear, so I thought it wasn't an aortic dissection. Can anyone help me understand why First Aid was wrong in this case? Thanks!
@pg32 The question stems states that there is no widening of the Aorta, not the mediastinum. Widening of the mediastinum is seen in dissection while widening of the aorta is seen in aneurysm. Also the intimal tear creates a false lumen between the intima and media. Hope that helps!