Message Number: YG2264 | New FHL Archives Search
From: Bruce Williams, DVM
Date: 2001-04-05 23:13:00 UTC
Subject: Re: FNA of Spleen, Phreddie

--- In Ferret-Health-list@y..., "Bonnie" <nigel.banks@s...> wrote:
> Our 2 1/2 year old Phreddie had a cyst removed from his leg on
> Tuesday and while he was under, our vet took a needle aspirate from
> his spleen (this week was the first time she had noticed that his
> spleen was enlarged and she thought it was huge). She wanted to do
> this because our oldest boy, Ziggy, has had an enlarged spleen
> we can remember and we never knew why - basically we wanted to know
> what an aspirate might show us. So in the interests of learning ...
> Following is the Cytology Report. May I please have a translation
> well as comments. I will pass any information along to my vet who
> a great personal friend, not overly knowledgeable about ferrets but
> willing to learn some stuff and let us go to someone more
> when she feels out of her league.
> DESCRIPTION: The two submitted slides have a very heavy background
> of peripheral blood with numerous platelets present indicating
> iatrogenic hemorrhage. The sample is very cellular and although
> preservation is poor due to the blood contamination, large numbers
> hematopoietic precursors can be identified. Most are erythroid and
> myeloid precursor, but several megakaryocytes are also seen. There
> may also be increased numbers of lymphocytes, but this is difficult
> to determine due to distortion of the cells.
> COMMENTS: The large hematopoietic population is compatible with
> extramedullary hematopoiesis, which is usually a response to
> peripheral anemia or compromised bone marrow function. The sample
> not compatible with lymphoma at this time, but reassessment of the
> spleen may be warranted if splenomegaly persists.
> End of Report.
> Thanks for this and for all the other information so freely given
> the people on this list. Kind of makes you think there's hope for
> mankind, doesn't it?

Dear Bonnie and Nigel - The cytology diagnosis appears accurate,
although I don't really agree with the comments. Extramedullary
hematopoiesis is a proliferation of immature red cells, white blood
cells and platelets - it is a benign lesion that is not consistent
the neoplasia. The most common cause of this lesion is chronic
inflammation, most likely from the gut. This chronic inflammation
most likely liberates inflammatory mediators which stereotypically
results in the upregulation of this maturation process. A similar
finding was shown years ago in rats which were injected in the
hindlimb with sterile turpentine, setting up a severe inflammatory
reaction. Within five days, all of the rats had markedly increased
spleens due to the extramedullary hematopoiesis.

This is a very common finding in ferrets. While severe anemia may be
a stimulus, it is far more common with chronic inflammation.
Additionally, the maturing pool of cells never seems to make it into
the circulation, which makes this response an interesting, but
ultimately not a beneficial finding in ferrets.

With kindest regards,

Bruce H. Williams, DVM, DACVP
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