Mast cell tumour case

RE: Mast cell tumour case

Tim Charlesworth — Wed, 02 Mar 2016 10:10:04 GMT

[quote user="David Mills"]

Hi Tim, thanks for the input.

I'm afraid we're at opposite ends of the spectrum me and thee. I understand where you're coming from but it's a world away from what's possible here at the RS in most cases. For instance, the reconstructive sx on this dog was around £200 - histo would be at least another £50 on top, which the owners simply couldn't afford. So, alas we can't 'always' send them off for histo, and whilst it may not add much to a referral bill, it would be an extra 25% on the bill here.

Prognosis? Yes it's nice, but it doesn't, in my sector, change much of what we can (or the clients can afford) to do. As this case shows - essentially left a choice between nsaids and preds. I'm not sure grading the tumour would change much apart from client expectations. Of course its always nice, but as a reason to always do histo? Not convinced.

Similar goes for staging tumours. Again, this case - admittedly not all details given at start - presented with a weeping, infected MCT of large size, and the only surgical option was a flap given its location. Possibly could have treated medically, but IME when they're as big as this one was this can be variable and fiddling while Rome burns springs to mind. But would staging have changed my approach? No, not really. The dog despite the regrowth is eminently happier, so I'm convinced surgery was the right option depsite the problems encountered since. I could be convinced by strong evidence to the opposite, but you must remember that your case load is highly selected and unrepresentative (as are those in most studies) - so when it comes to cutting corners, some of these may be theoretical, illusory or absent when trying to map them onto general/charity practice!

[/quote]

Fair enough!

RE: Mast cell tumour case

Aine Seavers — Wed, 02 Mar 2016 00:33:27 GMT

suggestions at lectures and discussions here I have attended over the last 5-7 years is the classic depth x fascia excision not always needed, reoccurence at site not left behinds but de novo occurrence, appearance at the margins not such a bad prognostic indicator in this immunoproliferative clumping disorder as the ones on edge as often the recruited group or lower mitotic index not the neoplastic ones. If this truly is an immunoproliferative disorder as specialists like Kevin Hahn state- the perhaps this is a scenario where medical targeting is better than radical surgery. Some lesions I couldn't excise ulcerated and weeping say on point of elbow with high mitotic index were suppressed for several years using preds and low allergen foods and protection from irritation by the Dogleggs hygroma shield-

RE: Mast cell tumour case

David Mills — Tue, 01 Mar 2016 22:12:34 GMT

Hi Tim, thanks for the input.

RE: Mast cell tumour case

Tim Charlesworth — Tue, 01 Mar 2016 11:52:17 GMT

All good and valid points! I tend not to see the "straight forward" MCT's these days so I do find myself staging all the ones I see. I must admit to having doubts about how useful sampling the spleen is but just when I consider not doing so I tend to get a met +ve sample so I keep on going. I find mets in about 10% of the cases I see. If your splenic samples are always too bloody - are you aspirating? - Just stick a fine needle in under u/s guidance and don't draw back. Lab tend to be very happy with diagnostic yield. We tend to stage the tumours under sedation, get the cytology back later in the day and operate the next day if all clear but appreciate if you're not operating all day/every day it does take time to find a decent "slot" for an APF surgery. Generally MCT grading is fairly consistent (esp with new Kuipel system) and we don't tend to see differing grades between biopsy/excision (unlike sarcomas) but NB cytological grading v unreliable and I'm talking about histol systems. I would always do histo on an excised tumour - it's a relatively minor expense compared to the main surgery and it gives you an idea of completeness of resection (admittedly not straightforward in MCT's) in addition to prognostic information. I wouldn't normally biopsy the MCT preop unless margins were a big deal (eg next to eye/nose) otherwise I would just go for the "normal" 2cm lateral/1 fascial layer deep. Most MCT's recurr due to incomplete deep margins. Your point about LN's is v valid - often cytologically "confirmed" mets are in fact non-neoplastic MC's being recruited to the MCT and these can only be differentiated on histology but if I was talking the owner through the ins/outs of resection/reconstruction and the owner was at all hesitant and only wanted to proceed if the surgery was going to be curative then I would get as much staging information preop as possible and accept the limitations of the sampling methods employed.

Sorry, bit of a ramble of consciousness but hopefully it helps!

RE: Mast cell tumour case

John Flynn — Mon, 29 Feb 2016 20:17:49 GMT

Always great to hear your input on cases, Tim, as is very instructive way of learning for me by reading comments on real cases.

Working in a pretty basic clinic, I must confess to having stopped trying to stage mast cell tumours before operating. My reasons were:

1) My ultrasound skills are pretty limited to identifying the organs and I never found changes anyway.

2) I don't like FNA'ing the spleen (usually get bloody non-diagnostic aspirates) and never had a case where this changed my plans. (Would be interested to know what percentage of referral cases you see have changes to surgical decision-making based on splenic aspirate)

3) I have had large numbers of mast cells on LN aspirates that on histology afterwards are described as reactive rather than metastatic, so I wouldn't choose not to operate based on cytology alone (and if I'm removing the adjacent LN, then I want to do the whole surgery en bloc often).

4) Loco-regional control of mast cell tumours with removal of gross disease (mass and suspicious draining lymph nodes) is almost always indicated as part of any treatment plan.

5) The histological grade not infrequently changes on removal of the actual mass versus pre-operative biopsy.

6) I find it hard enough to get the time in the day to schedule a significant reconstructive surgery like this and it wasn't unusual for it to literally postpone the definitive surgery by 4weeks or more doing pre-op staging/grading - I felt this time frame was possibly detrimental to curative intent.

7) Staging and mastinib or whatever can still be done after loco-regional control of disease if desired.

8) Excision is very frequently (>90% of the time?) curative for mast cell tumours - making treatment too complicated/expensive risks worse overall outcomes: i.e. failure to accept "corner-cutting" can lead to masterly inaction where nothing positive gets done for fear of the less-common negative outcome.

Also, while discussing, I was unconvinced that Ki67 added any useful information to the histopathology either on incisional or excisional biopsies.

I'm always keen to challenge my preconceptions though and think things through afresh. (Though I appreciate this thread is probably not the place for you to teach all the complexities of managing MCT's to the highest standard!)

John

RE: Mast cell tumour case

Tim Charlesworth — Mon, 29 Feb 2016 14:41:10 GMT

Hi David, I'm not sure if you did this or not so sorry if this sounds particularly unhelpful but just for others who may face similar cases.. It's always worth staging these tumours first if you are expecting to need to do a significant amount of reconstructive surgery. If FNA's of the local LN's +/- spleen etc came back as hooching with MC's then surgery is unlikely to achieve a great deal. Also - please always send these tumours off for histology. The grading is prognostic (with or without Ki67 etc) and this would have been useful in this case. I understand that finances can be restrictive in some of these cases but it's the only real way of giving the owner an accurate (ish) idea of what to expect in the future. I would also be very hesitant to give a dog chemo without any histological evidence of what we were dealing with.

Sorry if this comes across as being critical, I just think that too many corners can be cut sometimes!

Tim

RE: Mast cell tumour case

David Mills — Fri, 26 Feb 2016 17:33:35 GMT

Update on this case.

Dog was put on meloxicam and antibs for 7 days - masses have drastically reduced and the deeper firm tissue about 25% of what it was.

Owners have declined masivet/palladia and other chemo on cost/logistic grounds, so plan is meloxicam/ranitidine for now, then preds if former stops working.

Thanks for all suggestions and pointers.

RE: Mast cell tumour case

Aine Seavers — Thu, 18 Feb 2016 01:54:41 GMT

For owners who decline masti or palladia -Quite a few peer reviewed papers showing some efficacy of preds with or without surgery. I used to love Cimetidine for these cases as well but now find Ranitidine at pro-kinetic doses very good.

Appearance of mast cells at an original surgical site is not classified as relapse- they can simply occur de-novo at that site and not seeded or left behind per se.

For owners who decline masti or palladia -I would personally also put this dog on a low allergen diet like z/d especially if the dog had previous histories of allergies or skin issues- the immunoproliferative classification of this novel neoplasia as clumps of mast cells always makes me wonder if we should go back further in the process and try and reduce inflammation generally especially if dietary induced.

I have several dogs now over the years with inoperable or else operable but highest grade malignancy mast cells live several years on hills zd and preds and antihist-my personal findings and that of other vets who did the same is that it assists in the control of this condition-data not published but hope to one day do so when have the time.

RE: Mast cell tumour case

Rob Loxley — Wed, 17 Feb 2016 23:33:58 GMT

[quote user="Catriona MacIntyre"]Our referral oncologist recommends meloxicam in palliation due to its likely anti tumour effects. We certainly use it frequently in first opinion practice in mammary tumour and bladder tumour cases.[/quote]

Is there evidence for COX2 expression in MCTs to make us think it will help? More than preds?

RE: Mast cell tumour case

Catriona MacIntyre — Wed, 17 Feb 2016 22:55:51 GMT

[quote user="gareth maglennon"]

[quote user="Catriona MacIntyre"]

I think I would be opting for palliative care, or oncology referral.

In terms of palliative care, I think I'd give maybe antihistamines, but definitely something gastroprotective, e.g.omeprazole, and meloxicam. I seem to remember there is evidence that MCT patients are at increased risk of gastric ulceration, and meloxicam if often used in oncology now.

[/quote]what would be the rationale for meloxicam in this case? As a gastroprotectant probably an H2 blocker vs histamine production from the tumour rather than a PPI?

[/quote]

Our referral oncologist recommends meloxicam in palliation due to its likely anti tumour effects. We certainly use it frequently in first opinion practice in mammary tumour and bladder tumour cases.

Are PPIs not thought to work better than H2 antagonists in dogs? Ranitidine is a good prokinetic but not thought to be particularly good at increasing stomach pH.

RE: Mast cell tumour case

Richard Carter — Wed, 17 Feb 2016 16:35:34 GMT

Think I would repeat Sx - the inguinal arteries are anterior and the pudendal caudal, mark out the margins, pre-treat 24 - 48 hours with preds to shrink and reduce the MCT distribution to tumour only (hopefully) and cut down to muscle layer.

Think all the medical options are palliative at best, with some potential for very nasty side effects as well as very expensive unless settle for preds while if as has been suggested these may be superficial in the margins of the previous sx, it may be a case of who dares, wins. Won't know until you have tried.

Then do impression smears of your edges (cotton bud fine to roll along skin/ fat line to transfer to slide) and see if there was any chance

RE: Mast cell tumour case

Rob Loxley — Wed, 17 Feb 2016 13:39:47 GMT

[quote user="David Mills"]For those using masivet/palladia, what sort of monitoring are you doing? We don't offer chemo here as such, but I was under the impression the TKIs were at the safer end of chemo drugs.[/quote]

While TKIs are targetted therapies, they're still less than perfectly targetted. I've seen a couple of dogs with bad side effects on TKIs - one on each drug - so I usually start with monitoring of blds as per datasheet. This is often more than required for chemo...

RE: Mast cell tumour case

David Mills — Wed, 17 Feb 2016 11:15:18 GMT

[quote user="Linda Filshie"]Out of interest did you ready the flap first before resecting the tumour, and change kits before closing the repair? No judgement intended, either way, I only ask as I went to one of the Fitzpatrick referrals talks at LVS this year and its made me think about a bit how I do oncological surgery. [/quote]

It wasn't my surgery, but from what I understand from my rather OCD colleague, tumour was removed then kit, gloves, etc changed and personnel rescrubbed before flap preparation/suturing.

[quote user="Virginia Campbell"]Oh hard luck, that is a beautiful flap. I would kick the wall rather savagely and swear a bit, then find out if the owners are interested in palliative Masivet or Palladia. [/quote]

Quite. Obviously nice dog and owners as well, makes kick hardness requirement greater.

For those using masivet/palladia, what sort of monitoring are you doing? We don't offer chemo here as such, but I was under the impression the TKIs were at the safer end of chemo drugs. We're limited a little with being able to offer a full gamut of chemo hand-holding, so was hoping for 'light touch' approach - is this what people are able to do with these?

RE: Mast cell tumour case

Virginia Campbell — Tue, 16 Feb 2016 23:56:23 GMT

Oh hard luck, that is a beautiful flap. I would kick the wall rather savagely and swear a bit, then find out if the owners are interested in palliative Masivet or Palladia.

RE: Mast cell tumour case

Braden Collins — Tue, 16 Feb 2016 22:06:28 GMT

I don't think this dog is a surgery case. I would be reaching for chemo options. I would normally start with a vinblastine/lomustine combination, followed by palladia (we don't have masivet here).

RE: Mast cell tumour case

gareth — Tue, 16 Feb 2016 21:18:58 GMT

[quote user="Catriona MacIntyre"]

I think I would be opting for palliative care, or oncology referral.

[/quote]what would be the rationale for meloxicam in this case? As a gastroprotectant probably an H2 blocker vs histamine production from the tumour rather than a PPI?

RE: Mast cell tumour case

gareth — Tue, 16 Feb 2016 21:11:24 GMT

ditto that thought linda...I've seen referral cases where kit had not been changed and tumour cells were seeded along the incision line in the exact same location. Again, no criticism intended.

Sorry a revision to my post! I remember during my residency that my supervisor told me all about tumour seeding during oncology surgery and I was very sceptical at the time. However, I saw several cases where surgery involving this kind of flap was performed and MCT appeared weeks later all along the surgical scar. I'm not a surgeon at all, but I wonder how widely known this problem is?

RE: Mast cell tumour case

Linda Filshie — Tue, 16 Feb 2016 20:39:24 GMT

Out of interest did you ready the flap first before resecting the tumour, and change kits before closing the repair? No judgement intended, either way, I only ask as I went to one of the Fitzpatrick referrals talks at LVS this year and its made me think about a bit how I do oncological surgery.

(Sorry, a bit off topic but didn't think quite worth "tangenting")

RE: Mast cell tumour case

Catriona MacIntyre — Tue, 16 Feb 2016 20:01:53 GMT

I think I would be opting for palliative care, or oncology referral.

RE: Mast cell tumour case

John Flynn — Tue, 16 Feb 2016 19:28:16 GMT

Personally if my dog, I'd give antihistamines (+/-steroids) and euthanase when became clinical problem.

I can see the logic in giving something like mastinib (I don't think the KIT-typing matters), but I'm not sure I'd reckon that the cost-benefit was really there.

I wouldn't be that worried about damaging axial blood supply to flap at this stage (though I'd probably leave things another 2 weeks before cutting to be sure), however I would be worried about performing another non-curative surgery.