Taking margins

[Zuwie]

This question will certainly sound dumb, but better ask it now than suffer at the beginning of residency. Please keep in mind that English is not my first language. Anyway, with that being said, what is a margin and how do you take it?

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[mlw03]

someone more experienced will hopefully add to this, but i've never heard the term "taking margins" used - people "check margins" often, and that just means looking at the edge of a piece of tissue that was removed to see if that edge contains bad stuff (such as tumor, necrotic tissue, whatever) or if it contains healthy, normal tissue. if the edges have cancerous cells then people will say they had "positive margins" versus "negative margins" for normal tissue at the edges. when a margin is positive this has implications for the clinicians, whether it's the surgeon who may try to remove more bad tissue or an oncologist who'll now adjust the patient's post-operative chemotherapy because of the positive margin.

i'm probably oversimplifying it a bit and i know there's stuff i'm leaving out, but hopefully that helps you a bit.

 

[djmd]

Checking margins involves as stated above seeing it the margin is free of tumor (or sometimes viable tissue)

Taking margins is generally referring to taking margin sections.
meaning to submit sections of the margins (either shave or perpendicular.)

 

[l&usibari]

A surgeon will often check margins by frozen section in order to determine if more tissue needs to be removed during the surgery. For example, they will send a ureter margin to check for urothelial carcinoma. If the pathologist sees urothelial carcinoma or high-grade dysplasia, the surgeon will take out more ureter.

We always take margins when we are grossing malignant specimens (and even non-malignant specimens, just in case) that have been sent for permanents. For example, a colon resection with colon cancer in it, we will shave off the distal and proximal margins and submit them in separate cassettes. If the distal margin is positive for carcinoma, the surgeon knows to go back and take out more distal colon as there is residual tumor left behind.

 

[yaah]

Do you take margins on colons even if they aren't close (like 1-2 cm or less)? We are told not to, don't bother.

 

[yaah]

Do you take margins on colons even if they aren't close (like 1-2 cm or less)? We are told not to, don't bother.

 

[l&usibari]

Do you take margins on colons even if they aren't close (like 1-2 cm or less)? We are told not to, don't bother.

We always do margins. We take a shave if it's far away (say over 2cm) but take a perpendicular if it's close.

 

[CameronFrye]

Do you take margins on colons even if they aren't close (like 1-2 cm or less)? We are told not to, don't bother.

I go ahead and submit an en face margin from each side. If anything, that can be my reps of uninvolved. I'm not sure what our grossing manual says about it, but I try to be as mindless and preprogrammed as possible when grossing. That way, I don't forget anything.

 

[b&ierstiefel]

Do you take margins on colons even if they aren't close (like 1-2 cm or less)? We are told not to, don't bother.

we always take margins...perpendicular...never en face.

 

[deschutes]

For colon, if the margin is close take perpendicular, otherwise en face.

Agree with the pre-programmed. So much easier to reconstruct when the dictation vanishes into a passing black hole...

 

[yaah]

What's the point of taking a margin if the tumor is 5cm away though? You might as well randomly take a section from anywhere, if it has adenomatous mucosa it's going to be an incidental adenoma, not a skip lesion of the tumor. If it's an invasive tumor extending along the wall you'll probably see it, and even if it is it isn't going to track for 5 cm underneath the otherwise normal mucosa.

The only time a margin is important for colon cancer is if it's low rectal or if it is going deep into the fat and it is at the soft tissue margin.

I guess you could use your margin as your "uninvolved random colon" section.

 

[l&usibari]

I think this often comes down to demands of the surgeons rather than to reality. They want to see in writing that the margin was submitted and is definitely negative so they can confidently tell the patient "we got it all". From my experience, surgeons demands don't always make sense. Like sending a uterine leiomyoma for frozen section to see if it's cancer. I think after 30 years of practice, a pathologist can tell on gross examination if it's a benign leiomyoma, but we have surgeons who insist on freezing it just to make sure.

 

[djmd]

Agree with the pre-programmed. So much easier to reconstruct when the dictation vanishes into a passing black hole...

Sorry I can't not hijack with the black hole comment.

MULDER: No sonic boom did this. The construction worker who was killed had his spine crushed like a string of seashells, a circular abrasion on his torso in roughly the shape of an elephant's foot. Other workers at the site said they felt the ground shake followed by a faint whiff of animal odor in the wind.

SCULLY: Mulder, if you're still suggesting that the elephant did this, it just defies logic. Somebody would have seen it.

MULDER: Well, if somebody would have seen it, Scully, we wouldn't be here. Another vehicle would have left evidence of a collision - distress to the metal, or paint. I can see signs of neither of those things. I'd be willing to admit the possibility of a tornado but it's not really tornado season. I'd even be willing to entertain the notion of a black hole passing over the area... or some cosmic anomaly, but it's not really black hole season, either. If I was a betting man I'd say that it was, uh, ...

SCULLY: An invisible elephant?

Not really black hole season... classic..

Sorry back to pathology and if we are margin robots or not.

 

[b&ierstiefel]

What's the point of taking a margin if the tumor is 5cm away though? You might as well randomly take a section from anywhere, if it has adenomatous mucosa it's going to be an incidental adenoma, not a skip lesion of the tumor. If it's an invasive tumor extending along the wall you'll probably see it, and even if it is it isn't going to track for 5 cm underneath the otherwise normal mucosa.

The only time a margin is important for colon cancer is if it's low rectal or if it is going deep into the fat and it is at the soft tissue margin.

I guess you could use your margin as your "uninvolved random colon" section.

I've thought about this too...if the margin is grossly positive, then why submit margins? I do this out of habit but always wondered this. Because of this, I also don't routinely submit normal colon cuz you hit this twice by sampling the margins. I also but both margins in one cassette...so it's only one extra slide to look at.

 

[l&usibari]

I've thought about this too...if the margin is grossly positive, then why submit margins?

I ran into trouble with a lung specimen where grossly the tumor involved the pleura, but microscopically what I thought was tumor was actually fibrosis secondary to the tumor; the tumor itself was several mm away from the pleura. Doesn't happen as often with colon I guess.

 

[Zuwie]

Thank you all for your explanations. They will be very helpful.

 

[DarksideAllstar]

I've thought about this too...if the margin is grossly positive, then why submit margins? I do this out of habit but always wondered this. Because of this, I also don't routinely submit normal colon cuz you hit this twice by sampling the margins. I also but both margins in one cassette...so it's only one extra slide to look at.

I could see submitting a margin that was grossly positive for microscopy if only to fend off any future litigation issues. While no hypotheticals specifically spring to mind, it might be nice to whip out the block and show tumor on ink if questions arise. Same thing applies for grossly negative margins.

Anyway, if a tumor is more than a couple of cms away from the resection margin I would take an en face. If I can take a perpendicular section of the closest approach of tumor to the resection margin and get it in one piece into the cassette, then I do that (see doubtful attending, the margin is clear).

I always noted any puckering of the serosa, inked the surface underlying the lesion, made some cuts through it to find the apparent area of "deepest invasion", then took my section. Afterwards I removed the fat for my node search. I guess I did it this way in order to be more accurate with regards to staging (ie getting a section of the serosa before destroying the specimen for lymph nodes). No attending or senior resident ever complained about my methods, but I'm wondering what the protocol is for evaluating serosal involvement at other places: Do you leave all the fat on until you take your section or do you pull the fat off, then take a section? Seems to me like the latter method would have issues with it, but I'd be curious as to how people evaluate their serosa and handle the issue of having to find nodes (which seem to be always adjacent to the wall of the bowel, hence my question).

 

[deschutes]

What's the point of taking a margin if the tumor is 5cm away though? You might as well randomly take a section from anywhere, if it has adenomatous mucosa it's going to be an incidental adenoma, not a skip lesion of the tumor. If it's an invasive tumor extending along the wall you'll probably see it, and even if it is it isn't going to track for 5 cm underneath the otherwise normal mucosa.

The only time a margin is important for colon cancer is if it's low rectal or if it is going deep into the fat and it is at the soft tissue margin.

I guess you could use your margin as your "uninvolved random colon" section.

I think it comes down to how sure you are of your gross diagnostic abilities (or if you are an attending, that of your residents/PAs). When training path residents in bulk who don't yet have the big picture anatomy/pathology, it pays to teach a one-step grossing procedure that is for the most part fool-proof when followed to a T. I view the micro confirmation of a negative margin as a safety net. And then after that it becomes 'standard' for both convenience and safety.

Personally I'd much rather spend the 20 seconds taking a margin than the 20 minutes explaining why I didn't take it.

Also with pre-op radiation (not for colon specifically) and a mass of granular heaped-up mucosa, it can be difficult to tell where the residual tumour is.

I also but both margins in one cassette...so it's only one extra slide to look at.

What if one is positive? You ink?

I section for deepest invasion before removing fat.

 

[l&usibari]

Ink serosa, section for deepest invasion, then remove fat for nodes.

This is a good time to turn this thread into a bitch session about looking for lymph nodes in colon resections.

 

[DarksideAllstar]

What if one is positive? You ink?

I always ink proximal blue and distal green-- that way I can throw them into one cassette.

 

[DarksideAllstar]

Ink serosa, section for deepest invasion, then remove fat for nodes.

This is a good time to turn this thread into a bitch session about looking for lymph nodes in colon resections.

I probably had mentioned this before, but last year I had an FAP case that had at least 8 distinguishable (ie >2 cm), lesions that ended up being adenoca. It was pretty easy (unfortunately for the patient) to get nodes on that one. I ended up with some ungodly number.

 

[yaah]

Ink serosa, section for deepest invasion, then remove fat for nodes.

This is a good time to turn this thread into a bitch session about looking for lymph nodes in colon resections.

It's not just colon anymore. We had a signet ring gastric CA last week that there just weren't many lymph nodes on. I didn't gross it originally, but there were 6 total, and 2 were positive. Thus, it's confirmed metastatic. SUrgeon got upset because she "Did a D2 lymphadenectomy!" and thought there should be at least 15 lymph nodes. Where do they get these numbers? I feel like they are from legitimately conducted studies in the past, but how do you know how many lymph nodes there should be? I went through this thing with basically a fine tooth comb, and any lymph node that was 1mm or larger I found. Still, I only found 7 more (4 of these positive, but at this point does it matter?) As our attending said, he already has metastatic disease.

Surgeons apparently just cannot grasp the concept that # of lymph nodes vary from pt to pt. There are some colons where they pop out easily, and others where you find one or two nodes that are over 1mm. I have done a lot of lymph node hunting in my life (PSF and residency), have probably cumulatively spent several days of my life looking for colon lymph nodes, which is several days more than surgeons have done. I think I know of what I speak of. Then some *****s come out with studies that show if you submit all the fat you will find more nodes. Not really! Every time I have had to go back to colons at most I find one or two more really tiny nodes.

I wish someone would do a study that proved that if you spent a significant, careful amount of time looking for nodes in a colon and didn't find the popularly accepted number of 8-12 per segment that searching for more was a useless exercise. Unfortunately you CAN'T do that study because many residents don't know how to correctly look for nodes. But a properly designed study should show that in every case of colon cancer where the original gross only found 6 nodes or so with careful sampling, that finding additional nodes will NOT change the stage. Even if you find more, they will be tiny nodes and will be negative.

For example: My record node harvest in a colon was 100 in a right hemicolectomy. THe patient had TB. It was insane. I stopped counting at 100, and only went that far out of sheer morbid curiosity. BUt I have had low anterior resections where there was a good amount of fat and only TWO lymph nodes. ANd the entire fat was submitted! Shut up surgeon!

 

[l&usibari]

I've had very good luck going back and finding more nodes in my own specimens, but that's when I know I didn't do as thorough of a job as I could have. Having the fat and nodes sitting in formalin longer seems to make them easier to find.

 

[CameronFrye]

It's not just colon anymore. We had a signet ring gastric CA last week that there just weren't many lymph nodes on. I didn't gross it originally, but there were 6 total, and 2 were positive. Thus, it's confirmed metastatic. SUrgeon got upset because she "Did a D2 lymphadenectomy!" and thought there should be at least 15 lymph nodes. Where do they get these numbers? I feel like they are from legitimately conducted studies in the past, but how do you know how many lymph nodes there should be? I went through this thing with basically a fine tooth comb, and any lymph node that was 1mm or larger I found. Still, I only found 7 more (4 of these positive, but at this point does it matter?) As our attending said, he already has metastatic disease.

Surgeons apparently just cannot grasp the concept that # of lymph nodes vary from pt to pt. There are some colons where they pop out easily, and others where you find one or two nodes that are over 1mm. I have done a lot of lymph node hunting in my life (PSF and residency), have probably cumulatively spent several days of my life looking for colon lymph nodes, which is several days more than surgeons have done. I think I know of what I speak of. Then some *****s come out with studies that show if you submit all the fat you will find more nodes. Not really! Every time I have had to go back to colons at most I find one or two more really tiny nodes.

I wish someone would do a study that proved that if you spent a significant, careful amount of time looking for nodes in a colon and didn't find the popularly accepted number of 8-12 per segment that searching for more was a useless exercise. Unfortunately you CAN'T do that study because many residents don't know how to correctly look for nodes. But a properly designed study should show that in every case of colon cancer where the original gross only found 6 nodes or so with careful sampling, that finding additional nodes will NOT change the stage. Even if you find more, they will be tiny nodes and will be negative.

For example: My record node harvest in a colon was 100 in a right hemicolectomy. THe patient had TB. It was insane. I stopped counting at 100, and only went that far out of sheer morbid curiosity. BUt I have had low anterior resections where there was a good amount of fat and only TWO lymph nodes. ANd the entire fat was submitted! Shut up surgeon!

One of our thoracic surgeons got snooty with me over an esophagectomy specimen. He said that, "when he trained at WashU, the pathologists generally found 30 to 40 lymph nodes". I called bullsh*t on that, so I brought in the calvary (several attendings, including the former director of surg path at WashU). Of course, since that little dustup, the thoracic surgeons have been submitting more fat with the esophagectomy specimens, so of course our LN numbers have now gone up, which makes it look like we weren't trying before.

 

[djmd]

Our GYN Onc surgeons have gotten wind of the fact that sometimes sometimes total submits of lymph node dissections will turn up a few (avg >2) lymph nodes, they have been demanding this.. on all gyn node dissections...

and our attending won't tell them that it is inappropriate...

 

[deschutes]

Of course, since that little dustup, the thoracic surgeons have been submitting more fat with the esophagectomy specimens, so of course our LN numbers have now gone up, which makes it look like we weren't trying before.

How do you figure? I would have thought the logical conclusion to make would be that you get more nodes because they submit more fat now

Our GYN Onc surgeons have gotten wind of the fact that sometimes sometimes total submits of lymph node dissections will turn up a few (avg >2) lymph nodes, they have been demanding this.. on all gyn node dissections...

and our attending won't tell them that it is inappropriate...

How big are your dissections?? I almost-totally submit for these, in the "everything that doesn't melt into the paper towel gets submitted" sense..

 

[djmd]

How do you figure? I would have thought the logical conclusion to make would be that you get more nodes because they submit more fat now

How big are your dissections?? I almost-totally submit for these, in the "everything that doesn't melt into the paper towel gets submitted" sense..

I have seen the total submits take 10+ blocks and that is after lymph nodes were removed. I think one of those 10+ produced 1 or 2 small nodes.

To which my arguement is, how do you know that isnt just the tip of a node that was previously submitted... (not that have 13 negative nodes is different than having 11, but if those 2 'nodes' are the basis of your demands...)


The classic surgeon lackof understanding about lymph nodes. Was having a fellow watch me cut some nodes in. I pointed out a ~1-2 mm node I was submitting, and he say "Lymph nodes can be that small?" I scoffed "Under the scope I have seen lymph nodes that we half this size, if it has lymphocytes and a capsule/sinus... it is a node."