Phaeochromocytoma?

Re: Phaeochromocytoma?

sophia guymer — Wed, 03 Mar 2010 13:57:59 GMT

Thanks Charlotte, that makes me feel a bit better , will have to have a word with the rest about bp's too.

Sophia

Re: Phaeochromocytoma?

Charlotte Marshall — Mon, 01 Mar 2010 19:42:58 GMT

Sophie,

I have to admit to a slight bit of concern too. I've been in practice 12 yrs and the only phaeo I have diagnosed was post mortem 2 mths ago. I am beginning to think I might have been missing them! Perhaps I should try and encourage the practice to do bp's in dogs regularly just in case.

Re: Phaeochromocytoma?

Anne Pietersma — Mon, 01 Mar 2010 18:33:52 GMT

Hi Alex,

Although phaeos are reported to be dangerous to sample, it is possible to do US-giuded sampling in dogs and people, but one should only perform a procedure if comfortable with it! So your point is well made.

In general, a much less invasive technique for internal organs and that yields more cellular samples is to NOT use aspiration - but needle-only sampling. Multiple, very quick (and as long as possible) passes through the tissue without exerting negative pressure (no syringe). This works wonders for renal sampling for instance which with aspiration coupled to the sampling generally results in heavy hemodilution often preventing a diagnostic sample due to lack of renal cells. I have taught this technique to residents and transformed non diagnostic samples to diagnostic samples in one go (ie. they managed it at the first try). It also increases the chance of getting small groups of cells with some architecture preserved (eg. glomeruli). This is great for liver also yielding large rafts of liver cells. For liver especially, this can allow to determine if there really is an inflammatory component by decreasing hemodilution and also identifying leukocytes 'within' the large hepatocellular islands (with no associated RBCs) one obtains with needle only cytology. Otherwise inflammation in liver tissue is notoriously hard to detect reliably. (P.S: With kidney one has to sample tangentially across the cortex.)

Re: Phaeochromocytoma?

Alex Gough — Mon, 01 Mar 2010 17:50:50 GMT

[quote user="Anne Pietersma"]Cytology can aid diagnosis if a US-guided aspirate is possible. I've diagnosed phaeos based on cyto.[/quote]

Most would suggest that attempting to biopsy or FNA a suspected phaeo is a bad idea, very close to major blood vessels, and can cause a big spike in blood pressure. I appreciate that some of us are braver than others and that it is done, but I wouldnt biopsy my own dog this way (and that's not just in theory - I didnt!).

alex

Re: Phaeochromocytoma?

Anne Pietersma — Mon, 01 Mar 2010 17:22:44 GMT

Hi Jane,

Terminology aside, your findings make Cushing's (or hyperadrenocorticism!) unlikely (no persistent PU/PD, near normal alk. phos). although not completely ruled out, so I agree that the constellation of findings point to phaeochromocytoma. A urine cortisol:creat or LDDT could also be positive with chronic stress and we're no further advanced. Hyperadrenal dogs can be hypertensive though but this sounds rather high! Concurrent illness is also possible.

Non invasive techniques: Cytology can aid diagnosis if a US-guided aspirate is possible. I've diagnosed phaeos based on cyto. I'll ask one of our imaging colleagues about whether CT would enhance diagnosis and get back to you. Contrast studies to see if there is venous blood flow obstructions are a consideration...? Blood measurements of catecholamines are not useful though there are some reports on measuring them in 24-hr urine collections - not sure if these are available anyway (haven't heard of any lab measuring them).

Re: Phaeochromocytoma?

Alex Gough — Mon, 01 Mar 2010 08:27:05 GMT

I'm all for terminological exactitude, or pedantry! Here is one web definition, which distinguishes between Cushing's syndrome and Cushing's disease:

"Although it is rare, about two-thirds of endogenous (occurring within the body rather than from a source outside the body, like a medication) Cushing's syndrome is a result of Cushing's disease. The term "Cushing's disease" refers to Cushing's syndrome, which is caused by excessive secretion of ACTH by a pituitary tumor, usually an adenoma (noncancerous tumor). "

I must admit, I didn't know that there is no such thing as adrenal dependent Cushing's disease!

So as the lawyer said to the judge, after the judge had told him that he had been listening to him for an hour and was none the wiser, I may not be any wiser, but I am better informed.

Alex

Re: Phaeochromocytoma?

Evelyn Barbour-Hill — Sat, 27 Feb 2010 21:45:05 GMT

[quote user="Jane Dunnett"]My first thought whenever I have a dog with vague "unwellness" and enlarged adrenal is hyperadrenocorticism (we were also taught at Glasgow not to call it Cushings - "only the medics name diseases after themselves" ).[/quote]

This seems a good opportunity for the Grumpy Old Man to exercise a major bee in his bonnet.

"Cushings" is neither a disease nor a diagnosis. Cushing's syndrome is what it says, a syndrome. Cushing's syndrome is not a diagnosis, only a statement that the patient has a certain collection of symptoms.

If a patient does not have that collection of symptoms, it does not have Cushing's syndrome. It might still have hyperadrenocorticism perhaps, but it does not have Cushing's syndrome.

Re: Phaeochromocytoma?

sophia guymer — Fri, 26 Feb 2010 22:38:36 GMT

Thanks for that,Alex, feel bit better now

Re: Phaeochromocytoma?

sophia guymer — Fri, 26 Feb 2010 22:38:05 GMT

Hi Jane,

Didn't mean to give the impression I was doubting you, I was doubting my own abilities!

Re: Phaeochromocytoma?

jd2008 — Fri, 26 Feb 2010 17:50:04 GMT

Alex, Sophie - yes, confirmed by histo. In total I think I've diagnosed about 8 of these in 16 years - 4 of those have been in the past 2 years. So not hundreds but still a bit more than my fair share I think. Hence my earlier comment about zebras and hooves. I trained at Glasgow and will always have the words "common things are common" ringing in my ears!

The case I diagnosed a couple of weeks ago has still to be conformed histologically (no surgery done as yet) but has the following history: Came in from a branch clinic to my 24 hour centre suffering from acute abdominal pain, anorexia and vomiting. The dog has these bouts every 3-4 months and apprently always responds to symptomatic treatment. Looking back on its history i can also see it has sporadic episodes of ataxia with CP deficits which change in nature with each episode. It has persistently raised ALKP but only ever up to the 2000's. ALT had been 300 odd once upon a time but since then persistently normal. At one point someone had echo'd it and found a moderately enlarged adrenal. LDDST, ACTH stim and urine cort:creat normal on multiple occasions. It had spinal rads and a narrowed C6/7 disc space was found but the neuro signs were never accompanied by any pain. Anyway, fast-forward to when I see it: I trail through its clinical notes going back 3-4 years and realise that no definitive diagnosis has been made and the dog, between episodes was apparently very well. I take its BP and get 190. Check again the next day and get 238. I echo its abdomen and find an adrenal of 3.5 cm in length and 2cm at either pole. the dog responded very well to phenoxybenxamine (the difference in the dog after a couple of doses was remarkable) and my colleague in the branch then repeated LDDST which was again negative.

My first thought whenever I have a dog with vague "unwellness" and enlarged adrenal is hyperadrenocorticism (we were also taught at Glasgow not to call it Cushings - "only the medics name diseases after themselves" ). I do acth stim, LDDST and urine cort:creat, often multiple times, to rule it out.

I also think the waxing/waning nature of the signs can be a pointer. It really would be good if we could establish a normal range for urine catecholamines. The only challenge then would be working out how to transport 24 hours worth of urine to the lab

Once I did FNA an enlarged adrenal and when the cytology came back suggesting possible phaeo I realised what a monumentally stupid thing it was to do - thankfully the dog suffered no ill effects.

Jane

Re: Phaeochromocytoma?

Alex Gough — Fri, 26 Feb 2010 17:13:06 GMT

Absolutely Sophie, far more common for an adrenal mass to be Cushing's rather than phaeochromocytoma. Dont think that you are missing hundreds of these in general practice!

alex

Re: Phaeochromocytoma?

sophia guymer — Fri, 26 Feb 2010 17:04:31 GMT

Hello Alex and Jane,

Been following this post with more and more concern! I had to look it up!!

Ok I was out of practice for 3.5 yr before starting again for 2 am a wk two years ago but it hardly rang a bell, phaeochromocytoma!

So I was getting more and more worried about my own general knowledge.

Feel slightly better after your last mail, Alex, about it being rare after all. Am I wrong to think dogs with cushings (can) have a mass on the adrenal gland just as dogs with phaeochromocytoma and so could it be misdiagnosed if not send away for histo?

Sophia

Re: Phaeochromocytoma?

Alex Gough — Fri, 26 Feb 2010 16:00:49 GMT

Thanks Jane.

The only phaeo I have seen is my own dog, despite working in internal medicine referrals for the last 7 years, so I think they must be pretty rare. How did you diagnose yours, histo confirmation?

Alex

Re: Phaeochromocytoma?

jd2008 — Fri, 26 Feb 2010 11:46:45 GMT

Really sorry to hear about your own dog Alex. I think one of the hardest parts of being a vet is treating our own pets....

To be honest, we don't have proper invasive bp monitoring. We can set up CVP monitoring no problem but that alone is not enough and I personally would much rather refer our phaeos for surgery simply because of the aneasthesia and peri-op monitoring they need but the ones we've done in-house have been due to cost.

If my guy goes for surgery I'll be referring him to the RVC or the chaps at Davies.

I seem to have diagnosed more than my fair share of phaeochromocytomas over the years. I was under the impression they are supposed to be very rare but i wonder if they we have just traditionally under-diagnosed them? The fact that that I regularly check BP in dogs as well as cats may be part of it - 10 years ago I didn't.

Thanks again Alex!

Jane

Re: Phaeochromocytoma?

Alex Gough — Fri, 26 Feb 2010 09:48:27 GMT

Sorry, nothing more up to date on urine catecholamine testing than you have - my old dog died of this in 2006. Getting it out before it invades the vasculature sounds like a good idea - the prognosis for dogs that survive the surgery is variable but can be up to 3 years in the absence of metastasis, hence why I was prepared to put my dog through such an invasive procedure. Do you have invasive blood pressure monitoring? Apparently the blood pressure shoots all over the place during surgery - quite a challenge for the anaesthetist.

Of course as everyone else said, need to rule out Cushing's.

alex

Re: Phaeochromocytoma?

jd2008 — Fri, 26 Feb 2010 09:02:46 GMT

Thanks guys. Don't worry Alex, I certainly wouldn't dream of removing a phaeo myself! My colleague is an extremely good surgeon and has removed a few of these over the years (he does the cutting, I take care of the medical side) and has had very good success. I was thinking that CT may show up any invasion into vasculature which would make the surgery a lot more complicated - then I'd definitely be booking him in with Dan Brockman!

I did look into urine catecholamine testing - ironically I've just diagnosed a phaeo on another dog 10days ago, signs were a lot less subtle. Basically it's a bit of a complicated waste of time: you need to collect full urine output over a 24hour period and find a human lab for testing. No normal reference range exists for dogs as yet. If you have any more up-to-date info on catecholamine testing, Alex, I'd be really grateful.

I'm leaning towards doing a CT. In the meantime I've got him on a low dose of phenoxybenzamine and I'll run a LDDST and urine cort:creat on monday just for completeness.

One complicating factor in all this is that time is not on our side - otheriwse I'd sit back, monitor BP and check adrenal size every couple of weeks. I'm emigrating to Australia in september/october. Until the past couple of weeks I would have said that he was in perfect shape and capable of coping with the transition but there's no way on God's earth I'd put a dog with a phaeochromocytoma through a 24hour flight and 30 days quarantine Even if we do remove it I can't ignore the fact that a hefty percentage of dogs with phaeos have other malignancies lurking somewhere.....

I desperately want him to come with us but I need to know I'm not being unfair to him.

Life sucks sometimes

Jane

Re: Phaeochromocytoma?

Clive Ansell — Fri, 26 Feb 2010 08:37:21 GMT

I think my thoughts are similar to yours and would take me down the route of LDDST and urine crea:cortisol +/- more detailed imaging, CT or MRI.

Anaesthesia and surgery would be fairly risky if he has a phaeochromocytoma with all those catecholamines flying around.

Re: Phaeochromocytoma?

Alex Gough — Fri, 26 Feb 2010 08:36:38 GMT

Bizarrely my own dog had a phaeochromocytoma. His initial presenting signs were heart murmur due to volume overload, because the vasculature was causing an AV shunt. He then went on to become tachycardic with intermittent collapsing episodes. Ultrasound MRI and CT were done of the mass, which had invaded the kidney - CT was probably the most useful. Sadly my dog died on the table at the RVC after some heroic efforts by their team, for which I am very grateful. I would strongly advise you dont attempt to remove an adrenal tumour yourself - there are only a few surgeons in the country I would trust my own dog with for that procedure, and I chose Dan Brockman at the RVC.

Also I wouldnt biopsy a suspected phaeo - they can release huge amounts of catecholamines when touched which can be fatal.

There is a test we considered doing but didnt in the end to test for catecholamine metabolites - I dont know how available it is. I think it was for metepinephrine and normetepinephrine but I may have made those names up. I can try and look into it if you want to go down that route.

Alex