Melanocytic Dermpath Basics: Melanoma

A complete organized library of all my videos, digital slides, pics, & sample pathology reports is available here: kikoxp.com/posts/5084 (dermpath) & kikoxp.com/posts/5083 (bone/soft tissue sarcoma pathology).
Part 2 of my (in progress) video series about the pathology of melanocytic skin lesions. This video discusses the basic features and patterns that are commonly seen in melanoma, including asymmetry, pagetoid spread, confluent growth, abnormal/lack of maturation, severe cytologic atypia, and mitotic activity in the invasive dermal component. These are not hard and fast rules, just a helpful framework to serve as a starting point for understanding how to diagnose melanocytic lesions histologically. Exceptions exist for pretty much all of these things. Watch the video to learn more. Many thanks to my awesome medical student, Gray Orman, for transcribing this entire video so that closed captions would be available for viewers who need them! You can download the entire transcript of the video as a .docx here: bit.ly/2ZhUyMa.
Here's an excellent example of confluent growth in an acral lentiginous melanoma (WSI digital whole slide image): kikoxp.com/posts/2813/. And here's a video explaining the case in more detail: kikoxp.com/posts/2836/.
Topics Discussed (click timestamp to jump to that part of the video):
Asymmetry- 6:40
Pagetoid Spread- 7:30
Severe Cytologic Atypia- 11:15
Mitotic Activity in Dermal Component- 16:00 and 1:07:50
Abnormal/Lack of Maturation- 21:53 and 1:09:40
Confluent Growth- 32:55
Breslow Depth- 49:05
Regression- 1:00:10
Ulceration- 1:03:20
Pattern of Metastatic or Recurrent Melanoma- 1:10:05
Melanoma subtypes:
Superficial Spreading- 29:10 (and before)
Acral Lentiginous- 30:24
Unzipping Sign (Melanocytic Blistering)- 37:30
Eccrine Duct Wrapping- 39:30
Lentigo maligna- 50:30
Immunostaining- 52:30
Nodular- 1:03:10
Other videos that will help you better understand this topic:
-Normal Skin Histology: • Normal Skin Histology ...
-Nevus Basics: • Melanocytic Dermpath B...
-Melanocytic Immunohistochemistry: • Melanocytic Dermpath B...
Disclaimers: As I said in the video, distinguishing nevus from melanoma is serious business. My video does not replace the need for getting an expert consultation should you encounter a difficult melanocytic lesion in your practice. Also, melanocytic dermpath has areas of controversy with differing strongly held points of view. by various experts in the field. This video represents MY current views as of May 23, 2018. My views have changed since I started practice, and I suspect (and hope) that they will continue to evolve over time. You (or your mentors) may do things differently than I do. That's ok by me. I'm just sharing the way I currently think of melanocytic lesions with the hope that viewers may find it useful. My goal is to educate, not to create dogma.
This video is geared towards medical students, pathology or dermatology residents, or practicing pathologists or dermatologists. Of course, this video is for educational purposes only and is not formal medical advice or consultation.
Presented by Jerad M. Gardner, MD. Please subscribe to my channel to be notified of new pathology teaching videos.
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Facebook: / jmgardnermd

[@JMGardnerMD]

A complete organized library of all my videos, digital slides, pics, & sample pathology reports is available here: kikoxp.com/posts/5084 (dermpath) & kikoxp.com/posts/5083 (bone/soft tissue sarcoma pathology).

[@simplepathology7089]

Your videos are much better than any residency in the entire world. Thank you!

[@SandhyaRamachandran]

I agree totally

[@shadana.s.3575]

This video is priceless. You are an extraordinary teacher. God bless you.

[@ferhatozden]

You can not imagine how these videos help me at the beginning of adaptation to dermatopathology division. Many thanks Jerad.

[@daviderozze8325]

The way you teach is very effective, even if the subject may be very complicated and tricky. Thanks a lot for sharing your hints and tips from your personal experience, they’ll be very helpful.

[@nehapop]

Thank you very much. This is such a difficult topic with a lot of problems and difficulties with interpretation. So useful to find a talk that encapsulates all the key features! Please continue with more topics... dysplastic naevi and their grading /vs lentiginous naevi, naevi of special sites and spitzoid melanocytic lesions (something that we have such high interobserver variation and will be really useful for generalists like myself).

[@renanmartins445]

I'm happy for the existence of this video!! Thanks!!! We need more Path content on KZbin and you helped us, as students!!!

[@sitirichardson2389]

Excellent images and fantastic tutorial! Thank you Dr Gardner!

[@malinigoswami8526]

Never before seen such enthusiastic teaching and awesomely clear concepts!!

[@SandhyaRamachandran]

The best dermpath teacher; thank you so much for your efforts & time! feel so much more confident.

[@redflowers1000]

Thank you so much for your precious videos. They are actually the best lectures in dermpath online. 🙏

[@sameeraansar1343]

Fantastic tutorials. Your tutorials make the patient's and pathologist's life better!! Thank you

[@kneedownbrown]

Every few months I come back to this same video to remind myself of these basic principles! Thank you for at least the third time now!

[@JMGardnerMD]

Glad it was helpful!

[@loksachauhan54]

Thank you very much for the in depth presentation of this topic. Hope to see more such videos in future.

[@user-vx1zc3te4u]

Just wanted to say thank you for making these videos. You are awesome!

[@faithyou2682]

Thanks so much for your fantastic lecture! Very clear and well-versed!

[@belinda58sews29]

Wonderfully informative presentation! Thank you.

[@beelee87]

Thank you so much for your highly informative videos! I really like how you use the arrows to show exactly what you're talking about which is something that textbooks cannot do.

[@JMGardnerMD]

Thank you for the feedback I’m so glad you find the videos helpful! I am actually publishing a dermpath ‪Survival Guide‬ book that will have tons of arrows on the figure images. It should be out in July. You can preorder it here: bit.ly/2Te2haB

[@grigonius]

Great video! this came up exactly when i needed some info on melanoma.

[@ZainMehdipathology]

Thank you very much. I would feel much more confident in my exam now. And yes, topic of Dysplastic nevus and spitz nevus would greatly help.

[@JMGardnerMD]

Definitely have both on my list!

[@ritikabhat23]

Thank you so much. Nevus and Melanoma both topics are explained very nicely.

[@drm5431]

Very helpful video for pathology residents.Thank you.

[@fayghazvini]

Excellent and exceptional videos. Please continue to cover other topics too.

[@hayder5391]

For the first time i find myself understand how to diagnose melanoma…excellent presentation…thank you very much👍👍👍

[@JMGardnerMD]

Awesome! Thank you for that feedback!

[@reabitansky2769]

You make me love anatomic pathology course. thank you

[@paulo4856]

Thanks a lot! Excellent vídeo!

[@amaliyadipita6906]

Thank you Dr. Gardner 👍🏾👍🏾👍🏾👍🏾👍🏾

[@bmurad9026]

Thank you so much Dr Gardner

[@johnfazio2892]

Great review of melanoma basics.

[@Art.ASMR-You2]

Okay thanks hope to see more of these videos.

[@JMGardnerMD]

Have you seen my nevus basics video kzbin.info/www/bejne/oHy9daSAmt9soNk ?

[@clay3622]

Thanks for the content. I really appreciate it

[@boubaibiza8223]

thank you so much, precious video and very helpful

[@sabinacorreia7076]

Thank you so much for the effort. This was very helpful to understand the concept especially as we don’t see so much melanocytic lesions in our practice in India.

[@aikaterini-paraskevipierra6951]

Many-many thanks from Greece

[@MrAtarti]

Extremely useful, thank you.

[@JayApplebaum]

Great tutorial learned a lot - thanks

[@missknowall]

Thanks for another awesome video,

[@user-cn2zu8qp5u]

Thanks you a lot! Sir Jerad.

[@kinludovico]

Many thanks from Germany :)

[@JMGardnerMD]

Also check out my videos on melanocytic nevus basics ( kzbin.info/www/bejne/oHy9daSAmt9soNk ) and melanocytic immunohistochemistry ( kzbin.info/www/bejne/gKqxn55jgsmJp6c ). And be sure to read the disclaimer in the video description above.

[@hayder5391]

Thank you for this amazing presentation, but I wonder how many of the 21 thousand viewer are waiting for the *Advanced* video… I hope it would not take too long.

[@ahteshamulhaq6425]

Very nice and informative video. Thanks

[@sureshmenon1182]

Excellent! Thanks

[@madhudewan8207]

Good demonstration 😊

[@bouhnikdjalil7094]

Thank you so much, great !

[@JMGardnerMD]

Here's an excellent example of confluent growth in an acral lentiginous melanoma (WSI digital whole slide image): kikoxp.com/posts/2813/. And here's a video explaining the case in more detail: kikoxp.com/posts/2836/.

[@piyusha05n86]

Never understood Melanoma Better!

[@alejandragazarrosian1393]

Love your videos ❤️ thank you 🙌

[@JMGardnerMD]

Thank you! A complete organized library of all my videos, digital slides, pics, & sample pathology reports is available here: kikoxp.com/posts/5084 (dermpath) & kikoxp.com/posts/5083 (bone/soft tissue sarcoma pathology).

[@kathrinemariesteffensen8528]

Great video. Would love a video on Spitz nevi and spitz melanoma.

[@JMGardnerMD]

It’s on my to do list!

[@thomascrown3816]

totally echo the spitz issues mentioned below. sebaceous lesions would be great too (need to stop watching - I’ve spent my day doing this😱😱)

[@adelh5417]

Thank you so much for this very good vidéo

[@subui]

Thank you so much for the videos! Could I ask you a question? In the nodular melanoma example, it's a polypoid lesion. Should I measure Breslow and Clark as always? Breslow would be high and Clark level would be low?

[@JMGardnerMD]

Great question. Breslow is what matters. I usually also give Clark since some of my derms and surgeons like it, but I know many Dermpaths who don’t even provide Clark level in their reports. Some publications have suggested that the thick Breslow on polyploid melanomas maybe isn’t as bad as regular melanoma of same depth. But in my view, it’s still a thick melanoma usually with many mitoses, so it has significant potential for aggressive behavior in any event. I still give Breslow depth just like any other melanoma in my own practice. But some may do it differently than I do.

[@benotene4387]

Very educative video

[@imanyabary5958]

Really thank you 😍

[@humaarshad3044]

Excellent

[@user-sm2xc1wz8r]

Thanks a lot

[@kneedownbrown]

Thank you for another highly educational video. While I appreciate the features of malignancy that you pointed out I I still have great difficulty in putting a malignant melanocytic neoplasm into a discrete category eg lentigo maligna melanoma, superficial spreading melanoma etc... I understand that a Breslow thickness is a better prognostic indicator than the category that you assign it to but where I work I’m always expected to put a melanoma into a category. I would appreciate any tips to help with this and to explain the traditional melanoma categories and how they have evolved over time. Thank you again, I learn a huge amount from your channel.

[@JMGardnerMD]

I plan to make some videos about that in future. Most important thing is Breslow like you said. Some Dermpaths don’t ever provide subtype. I usually do when I can. Otherwise I say “unclassified Type”; I actually use that fairly often. Only real clinical significance is that lentigo maligna type often extends wider and needs bigger margins to get it clear and it tends to be challenging to read margins due to reactive atypia in background melanocytes from sun damage. On chronic sun damaged skin especially on head and neck of elderly, a melanoma will be lentigo maligna (LM) type in vast majority of cases and I will almost always call it that unless I have good reason not to. LM tend to have atrophic epidermis and patchy skipping of single melanocytes and/or nests along the basal layer. When well developed they get fully confluent and replace basal layer. LM Tend not to be very pagetoid but sometimes they are. Superficial spreading often on skin that is not chronically sun damaged has more epithelioid cells and prominent pagetoid spread. Acral lentiginous is on acral skin and usually has both confluence and pagetoid spread. Nodular Type has big nodule of invasive melanoma WITHOUT in situ spreading out beyond the invasive component. If in situ goes more than 3 rete to periphery of invasive component then I will classify it as whatever pattern the in situ looks like but I won’t call it nodular type even if a big nodule is there (confusing huh? I don’t make the rules I just teach them). Those are basic subtypes. Obviously there is a lot more nuance but I Hope that helps.

[@renugupta7419]

Like everybody else has written here that listening to your lectures is always wonderful way of learning. I am curious to know, listening to this lecture if there is possibility of over or under treatment of nevi and melanomas like that happened with prostate cancers at some point.

[@divyasethi1509]

Thank you 😀

[@user-ql6ze5uz5u]

Amazing thank you

[@doaab5898]

Thanks from Saudi Arabia 😊

[@nerom_de]

Very informative and interesting video. I think this helps a lot to understand how lesions are diagnosed. You mentioned that the histology is to be matched with the patient e.g. you mentioned the baby and the 90 year old. But what if you have a lesion "on the edge" with features of a melanoma and a reed/spitz/ heavily dysplastic nevus on a 30yr old? Is there some safe method to decide? Or would there always be some uncertainty?

[@JMGardnerMD]

There are some melanocytic lesions that are very difficult to classify with certainty, especially ones that have Spitzoid features and a lot of atypia. When I see those I usually show the case to my colleagues. Depending on the level of concern and how deep the lesion is, I sometimes send it out for additional expert consultation and molecular testing. My preferred place is usually UCSF as they have experts in difficult melanocytic lesions and they have advanced molecular testing available. You can discuss with your dermatologist and dermatopathologist if they think an additional consult and/or molecular testing would be helpful in your case. Please note that sometimes a consult plus molecular testing can take a few weeks or even up to a month depending on a variety of factors so just know that is normal and expected. My general thought is that if a patient or doctor is worried about the accuracy of a diagnosis, an additional expert consultation helps put everyone’s mind at ease regarding accuracy of the diagnosis. I’ve even recommended this for cases that I’ve seen and diagnosed if the dermatologist felt the diagnosis didn’t make sense or the patient was very worried. It doesn’t offend me at all. Patient care is always more important than ego! Of course, none of this is medical advice since I’m not your doctor and you are not my patient; Please be sure to discuss all of this with your dermatologist so they can make recommendations that are right for you personally. Best wishes for health and peace of mind.

[@nausheenhenna8950]

Superb

[@zainabnasir8943]

Thanks 🙏🏻 ❤

[@rashasamer8063]

Than you so much

[@musabfawwaz74]

You are the best

[@user-kc4dn4dp6l]

thank you so much for all your great efforts.....would you please clarify for me is confluent growth the same for lentigo maligna or is there any difference between them ?

[@JMGardnerMD]

Basically the same concept. Sometimes in Lentigo maligna there is more skipping between zones of confluence.

[@prashanthmadoori3973]

Thanks a tonne.

[@fersolobo]

Thanks for share us yours slades.

[@sara1363sara]

really great video, thank you. How do you diagnose a melanoma in situ in a background of a nevus and how can you be sure it is not invasive? I feel it may be a scary scenario !

[@JMGardnerMD]

Complicated and tricky for sure. PRAME can help in those cases but if it’s unclear I usually say atypical melanocytic proliferation with a comment explaining my differential and why I’m having difficulty with the case.

[@jimmycc935]

Love to watch such videos. Would be much better if you show IHC too.

[@JMGardnerMD]

I have plans to do a melanocytic IHC video in future.

[@zhengxiaomin3638]

Great video. Could you talk about adnexa tumor as well? Thanks.

[@JMGardnerMD]

I have a couple of videos on adnexal tumors already. Hope to make more in future. Nevus sebaceus: kzbin.info/www/bejne/bX6agJ9riNmIbbc. Spiradenoma & cylindroma: kzbin.info/www/bejne/mmLVhZSHZpeckNE. SCAP: kzbin.info/www/bejne/q4CXZ6mqjpKdbNE

[@tanthanhtran2155]

Thank you for the great video Dr. Gardner. I have a question. Can a dermatopathologist tell if the tissue sample they got from a punch biopsy come from the proximal nail fold or if it comes from the nail matrix? Like, how can you tell the difference?

[@JMGardnerMD]

This can be very difficult to figure out particularly if the biopsy is small and if no orientation or information is provided by the surgeon or dermatologist who did the biopsy. On a larger sample sometimes it’s easy to sort out where the nail fold and matrix and nailbed are but on a small biopsy it can be nearly impossible in my experience.

[@tanthanhtran2155]

@@JMGardnerMD if a doctor use a punch biopsy on the nail fold to diagnose subungual melanoma, thinking the punch tool will be able to go through the nail fold and collect tissue sample from the distal nail matrix, and then sent it to a dermatopathologist (4mm x 3mm x 2mm punch biopsy sample), is there a chance the dermatopathologist could have gotten a bad/inadequate biopsy sample and give a false negative diagnosis?

[@JMGardnerMD]

Nail biopsy can always have chance of false negative. Totally depends on the situation

[@valentinacastillo4491]

great video!!! please make moooore!!! :B

[@JMGardnerMD]

Have you seen this one? nevus video kzbin.info/www/bejne/oHy9daSAmt9soNk

[@jenifferburgos7802]

Hi, your videos are amazing!! Where can I send to you dermatological biopsies for revision ?? Tnx!!

[@JMGardnerMD]

Thank you! I’m sorry but I no longer accept cases for formal consultation. It just became too much work for me to handle!

[@hijabshah4682]

Hi. Very nice video. Can u post a video specifically about borderline melanocytes lesions and about the use of IHC in differential diagnosis of melanocytes lesions. Thanx a lot.

[@JMGardnerMD]

Borderline melanocytic lesions are still challenging for me. That would be a difficult topic to cover for a video but I’ll think about it. I do have a video about the use of immunostains for melanocytic lesions: kzbin.info/www/bejne/gKqxn55jgsmJp6c

[@haideralshammary3293]

Thanx sir u r great

[@SandhyaRamachandran]

after seeing ur videos I dont want to read the book !!! kidding ofcourse.. tanx for ur efforts...

[@kinludovico]

I have a tiny question Dr. Gardner: is there is any meaning/significance for melanin/melanocytes being in the corneal layer? when we see such a phenomenon, should we think in a way or another (malignancy/activity/pushing pattern)? or this represents simply no hint for anything? Thanks a lot in advance :)

[@JMGardnerMD]

Interesting question. I think it usually indicates abundant pigment production. I see it both in hyperpigmented nevi (lentiginous nevi especially) as well as in darkly pigmented melanomas. I don't think of it as a specific finding in general though. For acral melanocytic lesions, the pattern of pigment in the corneum can be used as a clue to nevus (pigment in troughs/valleys) vs melanoma (pigment overlying ridges/peaks).

[@eldermoreyjr]

@@JMGardnerMD Why does the pigment end up in one or the other (ridge vs furrow)? I've been wondering this through fellowship.

[@Chironex2010]

Have a shot each time he says "okay?" :-D But honestly, nice video!

[@hotmessmomtv4117]

For two-piece biopsies, one superficial and one deeper, would you measure Breslow by adding the thickest portion of the superficial biopsy (5.5mm) to the thickest of the most central portion (2.5mm)?

[@JMGardnerMD]

Yes that is usually what I do for two piece “double shave”. When I do this, I add a comment that explains that I added the two depths and therefore the breslow is a best approximation.

[@spiritoforient]

Much obliged from Pakistan

[@SandhyaRamachandran]

Hi Jerad: at 1:12:59 , if u hadn't told me its a melanoma, I'd hv thought it to be a nevus showing maturation ??

[@JMGardnerMD]

Yes, I agree. That case is very tricky from low power. It has a nevoid appearance. At higher power, it is obviously a melanoma though.

[@SandhyaRamachandran]

yes; tanq

[@evelyne7071]

Atypical or malignancy is “something” you would not want to meet in a dark alley.....That always been my “rule”.

[@madhudewan8207]

Molecular studies in melanocytic lesions, have you made video?

[@JMGardnerMD]

Sorry no I haven’t. I still find it pretty complicated!

[@raychand4776]

1:11:21How would one distinguish a purely intradermal nevus with some atypia and poorly discernible maturation from metastatic/recurrent melanoma?

[@JMGardnerMD]

That can be quite challenging especially without clinical information. Metastatic melanoma usually has a rounded ball shape that pushes up into the epidermis. It also often has mitoses. But I’ve seen cases that were hard to distinguish from nevus. I have more discussion of topics like this in my #dermpath Survival Guide book: bit.ly/2Te2haB ‬

[@jenifferburgos7802]

Have you seen recurrent nevus after excision in a sun expose area (nose) in the same place? What change you see?

[@JMGardnerMD]

Recurrent nevus usually has atypical melanocytes growing as single cells in epidermis over scar. For more info Check out my #dermpath Survival Guide book: bit.ly/2Te2haB ‬

[@KevinSmith-em7zk]

what is the difference between confluent growth and lentiginous growth?

[@ncorry8491]

Thanks, I was wondering if you could maybe do a 5-minute pearl type video on counting mitotic figures perhaps in a variety of melanomas. Personally, I find identifying prophase type mitotic figures quite difficult for instance at @25:15 , any tips or wisdom would be greatly appreciated.

[@lendzubow]

Are there immunostains that differentiate between melanoma cells and melanophages and if so, which? Thanks!

[@JMGardnerMD]

oh yes! I find ‪SOX-10‬ and MART-1 to be best for this, ideally with red chromogen (brown chromogen can be difficult to distinguish from melanin pigment in the melanophages). Melanoma cells are positive for ‪SOX-10‬ almost always and MART-1 usually but melanophages (which are histiocytes/macrophages) are negative for these markers. Desmoplastic melanoma and some spindle cell melanomas are MART-1 negative, but they wouldn't get confused with melanophages.

[@lendzubow]

@@JMGardnerMD Many thanks! So do the macrophages ingest melanin pigment alone or also some cytoplasmic and nuclear components of the actual melanocyte that could give false positives with Sox or mart-1?

[@kevinmoreal5200]

What would be the main difference from melanoma in situ vs lentigo maligna? Some sources make them seem similar but my staff sepsrates them.

[@JMGardnerMD]

Lentigo maligna is a subtype of melanoma in situ. It arises in chronically sun damaged in older adults, usually on the head and neck. It usually has atrophic epidermis with trickling single cell growth of atypical melanocytes scattered along the basal layer.

[@kevinmoreal5200]

@@JMGardnerMD Thank you!!

[@amanatsoomro4512]

Love from Pakistan 😍

[@JMGardnerMD]

Love from USA. 😊 I’m hoping to visit Pakistan to give some lectures sometime in the next few years. My friends Omar Chughtai and Kamran Mirza are working on arranging a visit. Fingers crossed!

[@evelyne7071]

When you started telling us: there’s a mitosis figure, I would say “No, that can’t be a mitotic figure…..look at how little it is”. I was used to seeing the big wild mitotic figures. Now I can see that these tiny cells mostly have small ink-black centers with dense almost granular eosinophilic cytoplasm. Almost all the ones you’ve ever shown me surprised me because, let’s face it, they’re really not impressive. I find that odd that in the middle of marked atypical/pleomorphism of most tumor cells, here sits this teeny tiny non descript mitosis. Odd.

[@ruchinasa]

soft tissue tumors. can we have a video

[@JMGardnerMD]

I have about 45 videos related to soft tissue pathology. More coming soon. kzbin.info/aero/PLkuwOd2JcINNV40nuefarOFoU55NNYG5f

[@ruchinasa]

@@JMGardnerMD Thank you so much. Can't tell you how much they are helping me revise ..esp 5 min pathology pearls. Lucky would be the residents who directly get to learn from you