Cutaneous Histiocytomas - to remove or not...?

Re: Cutaneous Histiocytomas - to remove or not...?

Rajat — Wed, 31 Oct 2012 00:06:37 GMT

As for the initial post (from 2010!) - I am one of the profiteering pirates - and I take off those histiocytomas that dogs will chew on incessantly and bleed all over the place and owners are fed up with.If it bothers the dog enough to lick for 2-3 hours perday personally I think it will be in the dog's interest to have it removed (imagine itching a lesion/plaque on your ankle/arm/A*Se for 2 hours every day till it is sore and bleeding?)

Others which repsond to abs where infected qnd/or respond to topical steroids I leave to regress. Doing inhouse cytology on these is quite straightforward too (most of the time!) - though external cytology is always offered and often I do both (inhouse for free external at normal charge) just to see how far off the mark I am

Re: Cutaneous Histiocytomas - to remove or not...?

Rajat — Tue, 30 Oct 2012 23:51:17 GMT

[quote user="Michael Woodhouse"]Crunch through entire pinnae with scissors[/quote]

Sounds a bit brutal. Do all your scissors 'crunch' ? If so may I suggest a good sharpening is in order Or better yet, try a scalpel blade - far less traumatic!

On a more serious note, a grade 3MCT will probably require more extensive surgical planning and/or radiotherapy (as in this case) and/or CT to look for mets and tumour staging..the surgery may be easy but that's not the end of the treatment. It's the beginning for a case like this.

Re: Cutaneous Histiocytomas - to remove or not...?

Emily Nightingale — Tue, 30 Oct 2012 21:57:04 GMT

Hi Michael .. This answer was a long time coming- sorry for the delay.

[quote user="Michael Woodhouse"]

[quote user="Emily Nightingale"]Turns out highly malignant mast cell tumour...requiring total pinnaectomy at referral centre.[/quote]

Emily - I appreciate your reply is a month old and you may not see this, but why refer possibly the easiest bit of surgery in the world? Done a few of these in cats with SCC of the ear tips [one was quite extensive and took ear at base] and they are simple. Crunch through entire pinnae with scissors, stitch skin to skin avoid cartilage. All healed perfectly.

[/quote]

I have done quite a few pinnaectomies in cats and one in a dog, but as far as I remember it was a grade three MCT and required subsequent radiotherapy so I sent it to the VRCC (also it was owned by one of the VN's mother's in law and insured to the hilt so was happy to refer)

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Thu, 09 Dec 2010 13:03:34 GMT

Picture from my HTC - good for a quick pic Pre-stained slide (diff-quik I think)

I struggled with this are (not in this view) but this was hootching with mitoses but overall freq. MNGC and binucleates suggests it is a Plasmacytoma ? Dog is 13yrs off its ear - I did suggest biopsy on this one as the atypia and anisokaryosis was of concern!

Re: Cutaneous Histiocytomas - to remove or not...?

Michael Woodhouse — Thu, 09 Dec 2010 00:46:04 GMT

[quote user="Emily Nightingale"]Turns out highly malignant mast cell tumour...requiring total pinnaectomy at referral centre.[/quote]

Re: Cutaneous Histiocytomas - to remove or not...?

Vikki Halliday LLB — Wed, 08 Dec 2010 23:16:53 GMT

I can be an equally opinionated frustrated ophthalmologist........

and PS. isn't it amazing what you can do with an iphone? I frequently take photomicrographs with it and email them to A.N.Other lab for an opinion that day!

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Wed, 08 Dec 2010 22:14:22 GMT

No probs - sounds like a good plan Don't worry were all undervalued, I didn't take it personally

Yours (an opinionated pathologist) Richard

Re: Cutaneous Histiocytomas - to remove or not...?

Vikki Halliday LLB — Wed, 08 Dec 2010 21:40:16 GMT

Thanks Richard, yes they most likely look like neutrophils, but there were a few of what looked in my poorly educated opinion, eosinophils, however I can never be really sure unless they are obviously miltilobular nuclei like the ones appearing here! There are some other pics, but i'm at home now, i''l try and get them on Fri.

My feeling is that this is a histiocytoma given the age, breed, location and clinical appearance, but I thought I would ask you opinion as you may have had the impression I undervalue pathologists!

I think we will watch this one for a week or so, as I expect to see it start to regress.

Dont think it it lymphoma either, as remainder of slide very few lymphocytes, and a very erythematous mass.

Cheers for the opinion!

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Wed, 08 Dec 2010 19:19:17 GMT

Hi Vikki

IMHO those 2 polymorphs are neutrophils but I guess they are not the ones you mention as eos? Sometime you can get quite a few eos in HCT's but most often not. Those round cells certainly have enough cytoplasm for histiocytes and ovalish nuclei with no obvious granules. They doo seem to have prominent nucleoli - my ddx would be HCT was there are some small lymphocytes as well. Lymphoma seems unlikely so that about it If there are loads of eos I would biopsy just in case its a poorly diff MCT?

Re: Cutaneous Histiocytomas - to remove or not...?

Vikki Halliday LLB — Wed, 08 Dec 2010 18:45:16 GMT

Histiocytoma?

Just FNA'd this from a 1cm red nodular mass on the neck of a 4 month old Labrador.

Can't see any mast cells, but eosinophils present making me suspicious......

Re: Cutaneous Histiocytomas - to remove or not...?

Emily Nightingale — Sun, 07 Nov 2010 21:15:07 GMT

Small 3mm wide sl raised uniform nodule masquerading as a histiocytoma on the medial pinna of 18 m.o. lab which the owner asked whether we should remove or not as the patient was coming in for routine castration.

We advised the client it was likely to be a histiocytoma (age of patient, localisation, appearance of mass) so removal not strictly necessary but we could remove it and send it for histology..which we did..

Turns out highly malignant mast cell tumour...requiring total pinnaectomy at referral centre.

I realise the thread is mainly about what to do when you know it is a histiocytoma, but I have seen many masses that I have said to "leave" and they will regress without having done any further cytology etc primarily due to cost restrictions, which would not have been wise in the above case..

Re: Cutaneous Histiocytomas - to remove or not...?

Alison Farr — Sun, 07 Nov 2010 20:27:47 GMT

The point about Diff Quick sometimes not staining the mast cell granules well is important although, fortunately, not so common. I saw a case at IDEXX where the practice sent in their stained slide which showed a fairly ugly looking round cell population without any cytoplasmic granules evident, but plenty eosinophils in the background. They also sent some unstained slides which we stained up and showed abundant granulation. The eosinophils can be a useful feature to look out for - you will often find them hanging around mast cell tumours.

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Sat, 06 Nov 2010 12:08:00 GMT

And negligible risk in doing cyto to confirm you gross diagnosis

BTW A= HCT, B=MCT aparently :)

Re: Cutaneous Histiocytomas - to remove or not...?

Hannah Wynne Richards — Sat, 06 Nov 2010 11:31:05 GMT

In other words Risk of GA in 95% less than risk of guessing in 5%

Wynne

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Sat, 06 Nov 2010 11:06:02 GMT

[quote user="Rob Davis"]

[quote user="Richard Fox"]

Which one is a MCT? A or B

[/quote]

Don't tease us..... I'm guessing both, but both horrible areas to achieve decent margins

[/quote]

There you go - its down to guessing sometimes. So why not just stick a needle in it to find out

MCT:

HCT:

http://www.vetsurgeon.org/media/32/default.aspx

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Sat, 06 Nov 2010 11:04:55 GMT

Christopher is correct. Sorry if I sound condescending or pompous but the grading scheme was created via histopathological examination of biopsies NOT by cytology - cytology can be a guide as to the grade but one of the most important criteria of grade is the number of mitoses per 10 x40 fields (mitotic index) - this therefore is impossible cytologically.This is a subject I am passionate about

If the cells are well differntiated on cyto I would suggest a low to intermediate grade tumour but always suggest incisional or excisional biopsy to indicate grade. BTW grading is not finite! and Ki67 seems in my view not to give a lot more info - we are dealing with biological systems and they do not always read the text book

Re: Cutaneous Histiocytomas - to remove or not...?

Rob Davis — Sat, 06 Nov 2010 11:00:27 GMT

[quote user="Richard Fox"]

Which one is a MCT? A or B

[/quote]

Don't tease us..... I'm guessing both, but both horrible areas to achieve decent margins

Re: Cutaneous Histiocytomas - to remove or not...?

Christopher Saul — Sat, 06 Nov 2010 10:54:40 GMT

..I will not be drawn into guessing based upon gross appearance alone ....

Re: Cutaneous Histiocytomas - to remove or not...?

Richard Fox — Sat, 06 Nov 2010 10:46:34 GMT

Looking at a MCT as we speak :) On a Saturday, are you maaad? No on duty

Test:

Which one is a MCT? A or B?

Re: Cutaneous Histiocytomas - to remove or not...?

Christopher Saul — Sat, 06 Nov 2010 10:42:57 GMT

.... NB you can't reliably grade an MCT by cytology alone of course so I would give all known MCTs a reasonable margin even if I clinically suspect a low grade (assuming it is surgically realistic to do so)

Re: Cutaneous Histiocytomas - to remove or not...?

Christopher Saul — Sat, 06 Nov 2010 10:40:32 GMT

Not a bad option at all, as most histiocytomas are in young animals who are of relatively low anaesthetic risk. I suppose I just love to aspirate because I'm a medic

The only other thing I'd say in favour of aspiration is.. if you do manage to achieve a diagnosis by cytology, you can then plan the surgery more appropriately ( margins etc).

Re: Cutaneous Histiocytomas - to remove or not...?

Bob Russell — Sat, 06 Nov 2010 10:40:17 GMT

[quote user="Charlotte Marshall"]

I give the client the choice but I do end up removing a fair few because the dogs traumatise them. I have always suspected they must be itchy.

[/quote]

If they are bothering the dog or the owner I remove them. Surgery is minimally invasive and low risk. I have no problem with this. The owner is always informed and given the choice of wait and see, FNA and removal. I do not routinely get path if I am satisfied it is not sinister but will store the samples for several months in case of problems.

I have had one that was a mast cell tumour and it was only a gut instinct that made me uneasy - to this day not sure what it was that seemed different but I decided to give a wide margin and was very pleased afterwards that I did!!

Re: Cutaneous Histiocytomas - to remove or not...?

Hannah Wynne Richards — Sat, 06 Nov 2010 10:33:04 GMT

I usually remove-probably being old-fashioned, but FNA wasn't so popular when I qualified, and I don't really trust it,as could get an unrepresentative sample-prob being old-fashioned again

Wynne

Re: Cutaneous Histiocytomas - to remove or not...?

Christopher Saul — Sat, 06 Nov 2010 10:24:33 GMT

[quote user="Hannah Wynne Richards"]

The realproblem is the impossibility of distinguishing the benign (histiocytoma ) from malignant (MCT ) on visual examination. Back in the days when I employed an assistant, I once booked in a youngish dog for a lump removal. My assistant who was in a stroppy mood was on ops, the day it came in for surgery, and sent it home. To cut a long story short-it was a MCT and spread, and the dog died-that case caused me a LOT of grief, + FOC palliative treatment

Wynne

[/quote]

That sounds a nightmare Wynne, I sympathise. That's why I'm such a fan of cytology; MCTs in particular usually exfoliate pretty well on aspiration I suppose a dilemma is when to aspirate.. do you aspirate every apparent histiocytoma as soon as you see them or do you monitor them closely and aspirate if they fail to regress; I suppose that's a matter of clinical judgement...

Re: Cutaneous Histiocytomas - to remove or not...?

Hannah Wynne Richards — Sat, 06 Nov 2010 10:09:13 GMT

Wynne