There were Howell-Jolly
bodies in the most recent EQA morphology survey. Apparently...
Howell-Jolly bodies are
little fragments of the red cell nucleus. They are most commonly seen
in patients with splenectomies purely because the spleen gets rid of
them. They can be seen them without any special staining. They appear
dark, round dots in the red cells.
Interestingly whilst
Howell Jolly bodies were fresh in my mind I read this article on
Facebook. (Facebook isn't all drivel - it's a useful source of
CPD!!)
http://www.pathologystudent.com/?p=9812
Because they both begin
with the letter "H" there are those who get
Howell-Jolly bodies confused with Heinz bodies. (Apparently).
I found this odd - you can't see Heinz bodies without doing
supravital staining. I'm old enough to remember Heinz bodies being an
unwelcome complication of reticulocyte counting, but realistically
who counts retics that way these days?
Heinz bodies are most
commonly found in G6PD deficiency. They are denatured globin chains
formed when the haemoglobin molecule undergoes oxidative attack. When
this happens the haem molecules are recycled, but the globin chains
adhere to the inside of the red cell membrane forming Heinz bodies.
These are present in cases of G6PD deficiency, but cannot actually be
seen without performing supravital staining.
It is worth bearing in
mind that macrophages in the spleen chop Heinz bodies out of red
cells forming the things traditionally called "bite cells",
so on seeing bite cells it may well be worth considering performing a
supravital stain.
Having said that I
perform a G6PD assay (on a patient as opposed to an EQA sample)
about once a year, and in thirty years I think I've only once seen a
result which hinted at a deficiency, so Heinz bodies are firmly in
the "obscure" category whereas Howell-Jolly bodies
are seen on a weekly basis (if not more often).
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