Melanocytic Dermpath Basics: Benign Nevus

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 1 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 benign melanocytic nevi, including: symmetry, maturation, basally-oriented melanocytes (i.e. - lack of upward pagetoid spread), well-spaced junctional melanocytes (i.e. - lack of confluent growth), bland cytology (lack of atypia), and low or no mitotic activity. 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!
Topics discussed (special thanks to viewer Ronald Chan for listing these timestamps!):
0:01 Introduction and disclaimers
4:03 Shave biopsy
6:03 Symmetry
9:06 Junctional, Intradermal and Compound Nevus
15:02 Maturation and type A B C melanocytes
26:10 (Lack of) Cytological atypia
34:20 Dysplastic nevus
45:44 Congenital features
1:00:41 Neurotized look
1:02:30 Fat metaplasia
1:03:17 Pseudovascular changes
1:07:22 Hyperpigmentation
1:09:18 Subcutis extension
1:12:09 Nevus vs Neurofibroma
Other videos that will help you better understand this topic:
Normal Skin Histology: • Normal Skin Histology ...
Melanoma 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 April 5, 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.
Follow me on:
Snapchat: JMGardnerMD
Twitter: @JMGardnerMD
Instagram: @JMGardnerMD
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)

[@luisbriones9191]

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[@paulmiller9020]

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[@annaj7058]

Dr Gardner, I'm a first year anatomical pathology registrar and just wanted to say your tutorials have helped me immensely during my first year of training so thank-you, you are the GOAT of dermatopathology

[@a97cck]

Thank you for the great video and all the beautiful slides! 0:01 Introduction and disclaimers 4:03 Shave biopsy 6:03 Symmetry 9:06 Junctional, Intradermal dermal and Compound Nevus 15:02 Maturation and type A B C melanocytes 26:10 (Lack of) Cytological atypia 34:20 Dysplastic nevus 45:44 Congenital features 1:00:41 Neurotized look 1:02:30 Fat metaplasia 1:03:17 Pseudovascular changes 1:07:22 Hyperpigmentation 1:09:18 Subcutis extension 1:12:09 Nevus vs Neurofibroma

[@KyrieW]

Bump! Thanks for the time stamps!

[@JMGardnerMD]

Many thanks, Ronald Chan! I've added your list to the video description and credited you for typing these up. You saved me a lot of time. Thank you!

[@shomaniv]

Thanks for the time stamps :)

[@margaritamunozdetoro4072]

Dr. Gardner, thank you so much for this and all your videos! The idea of high quality material accesible to everyone around the world is gamechanger. You are an inspiration! Thank you for your work!

[@KingElrosTarMinyatur]

Love when you add in things not found in textbooks like "I don't add this into the diagnosis" - truly, your one of my favorite dermatopathologists!

[@JMGardnerMD]

Thank you! 🙏🏻vMy dermpath survival guide book is full of practical pearls about how to write reports and deal with complicated daily problems in dermpath. You might find it helpful. bit.ly/2Te2haB ‬

[@ShashidharVenkateshMurthy]

Great teaching Great service to global Pathology ...!

[@eniomm1]

Excellent explanation, as always! Your videos have helped me a lot with my dermatopathology routine. Thank you very much, doctor Gardner.

[@user-cz8yd9kf2y]

Thank you sir! Great videos. Thank you for making dermpath as simple as a halwa (South Asian sweet dish). Love and Respect from Pakistan!

[@missknowall]

Thank you so much for another amazing video. You are a gifted teacher. Hope you continue to spread the light.

[@shomaniv]

Thank you Dr.Gardner. These lectures are of immense help and the way you have put the timestamps for longer lectures helps immensely to revise the topics.

[@JMGardnerMD]

Thank you! I’m working on adding more time stamps as well as subtitles/closed captions.

[@machteldsimpson6401]

I just found these videos ad they are extremely helpful. Thanks heaps, much appreciated :))

[@RaulRodriguez-sh6vb]

Now I can say I have learned and feel more comfortable when dealing with a melanocytic lesions. You have encouraged me to think about doing a Dermpath fellowship Thanks a lot

[@annitah2o]

Great video! Thank you for sharing your knowledge and your beautiful slides. Greetings from Spain.

[@rashasamer8063]

Thank you so much for your extremely amazing effort These videos are very beneficial and have added alot to my information

[@grigonius]

You are a great teacher dr. Gardner! ty for all the informative videos

[@monamohsenabdo752]

this video is really amazing..thank you so much for every single info in this masterpiece.

[@szwalsam]

Excellent teaching session like many of your videos, thank you for the time and efforts.

[@vinvinvino3176]

Thanks a lot Jerad...you have helped a lot of us general pathologists by your very educative videos!

[@mkhan7499]

I second you. Amazing video.

[@pedromarciano2503]

congratulations but mostly thank you very much! it is amazing this opportunity to have you as a teacher! best wishes from Brazil! im now on residency program from Universidade Estadual Paulista - UNESP (Botucatu-Sao Paulo)

[@chrisphillips8044]

These are all fantastic videos - thank you

[@navodakumarasinghe8135]

Thank you very much for the wonderful lectures. Important things are explained really well. I started loving dermpath thanks to your videos!!!

[@logancosta3419]

Thank you, that was a very helpfull video! Hugs from Brazil

[@radosawwujec959]

I'm incredibly grateful for all that effort you put in those videos. I'm about to start my path residency in a month and what you say is waaaay more digestible than any textbook. What i value the most is you tell which part is important and what not as much as well as those basics that textbooks rather omit not bothering with such an "obvious" stuff. Huge thanks from Poland

[@evelyne7071]

As a nevus novice, I thank you. The explanation about maturation is super interesting and an important benign feature. I like the fact that melanocytes themselves are not melanoma-laden like the squames and the macrophages down below.

[@engvoc5318]

Thank you so much. I learn a lot from your videos everyday

[@ncorry8491]

Thanks a true treasure ❤️. Looking forward to the video on dysplastic naevi , would be nice to just see your approach to a variety of dysplastic naevi, perhaps touching on more difficult cases on the borderline between dysplastic naevi and melanoma.

[@gladysaloyomola8649]

Loved it.! Thank you this is wonderful very nice for learning.

[@pedrorodriguez9017]

Many thanks for your amazing effort, really really helpful.

[@ikbalelkholy558]

Thanks Dr Gardner very much

[@abhijeetwaghmare2794]

Best video that I have seen to clear concepts... Thanks a lot..

[@stellagarvie897]

I can't emphasize how helpful this video is... Especially, considering that melanocytic lesions are generally a horror of a doctor in training. Thank you so much! Great work.

[@gordonchristophertubo3164]

This is just... The best. Edit: This is my 3rd watch btw.

[@lakshmid1953]

thank u so much for making these life saving videos!!

[@eduardob3036]

Thank you so much for an excellent video!

[@gerikn20]

Great job again! Thank you so much!

[@Zahra-mo4bg]

Thank you so much Dr gardner

[@vikaspawar6847]

It's an amazing video sir. Got the excellent information . Thank you v much.

[@shalinikk5832]

Thank you so much for the amazing teaching 👍

[@alzahraakhalil142]

Many thanks, excellent explanation

[@ThisMichaelBrown]

Superb....where were you 25 years ago!? Ha....thanks man. So incredible that young (and old, ha) path folk now have access to this these incredible resources!

[@JMGardnerMD]

Thank you for the kind words. I’m working hard to make as much content as I can so that 25 years from now, hopefully no one will have to say that! Im working to teach pathologists in other sub specialty areas how to make videos and similar teaching content. My dream would be to see all of pathology freely available online to the whole world especially those who live and work in the developing world and in other places where there are limited financial and educational resources.

[@ahmed_atef_agour]

Thanks for this valuable lecture.

[@SadafMohajerani-cl1qe]

Thanks a lot , very useful and comprehensive 🙏👏

[@florianburkhart8090]

Thank you for the exceptionally great teaching video! It gives priceless help for me, getting deeper in dermpath as a dermatology resident.

[@DuaaHelal]

Greetings from Egypt Thank u for the great informative video

[@christinagoveas5003]

Amazing Lecture Dr Gardner :)

[@belinda58sews29]

Great video! Thanks.

[@sararashid8761]

Very very helpful lecture , thank you so much.

[@Maryam_77777]

The ultimate way of teaching sir. Hats off to you.

[@ayeayewin8690]

Thank you Sir. I like all your lectures.

[@jessmilt9403]

Thanks!!! Your videos are awesome

[@kylevincisolano9920]

Thank you doctor! A great help in pathology residency! cheers from the Philippines! Godbless

[@AhmedGamalPost]

Amazing video I am waiting for the next video thank you . Prof

[@sameershrestha6171]

Your videos have made derma path look reasonable and easy. Thank you. as a dermatologist, if it is possible to show also the clinical image of the histological sections that you were describing will be more add on and fruitful.

[@DocRicForensicSpecialist]

Thank you Dr.😃

[@Vlad_Kowach]

thanks for sharing your knowledge. It's very helpful and interesting. Skin lesions very hard and melanocytic lesions is even harder. that's why I'm glad to find your channel. thank you doctor Gardner

[@JMGardnerMD]

Agree…They can be quite hard! Happy I could help. Also…You might like my Twitter/social media 101 guide: kikoxp.com/posts/15217. I also highly recommend creating a professional profile on KiKo (it’s free! Here’s mine: kikoxp.com/jerad_gardner1). 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).

[@Vlad_Kowach]

@@JMGardnerMD this links will be really useful to me. thank you!!!

[@anupambrahma5659]

thanks a lot. cleared my concepts

[@kevinmoreal5200]

You are a legend!

[@DerrickAdamsdermatologist]

excellent video. thank you

[@antoiroets7405]

Great video thanks!

[@user-cn2zu8qp5u]

Thank you! finally! :)

[@magihna]

Thank you!!!!

[@arahmanabdelrahman6661]

I am very thankful to you

[@yasirmohammedali]

Hi ... Thank you again for the amazing videos

[@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).

[@shomaniv]

It will be great Dr. Gardner if you can kindly put a video about different types of nevi and melanoma. Thanks alot

[@JMGardnerMD]

Already started this. I’ve made a playlist of my melanocytic videos that I will add to over time as I create new ones: kzbin.info/aero/PLkuwOd2JcINM5tNZK6eDGNDxlW1d_WzWO. Desmoplastic & spindle cell melanoma are coming up soon on my video to-do list.

[@hayder5391]

Thank you for this nice video👍👍

[@user-li8hk5yh6s]

Great channel

[@mohitrajpal266]

Thanku sir for your guidance I feel extremely grateful to you

[@jsegalbts]

thanks jared! your videos look beautiful and I appreciate the new look of the youtube tags.

[@JMGardnerMD]

Thanks for the feedback! I like the new thumbnail images. Found a nice website that lets me make them easily for free. Adobe Spark.

[@bouhnikdjalil7094]

Thank you so much, it's verry important :-)

[@joyreang7099]

thank you. how I wish to work under you. wow!

[@manarm8704]

Thank u so much 🌹

[@marynandinisingh3808]

Thank you 😊

[@dr.tintinthein8566]

Thank you very much

[@piyusha05n86]

Thankyou sir!

[@nilegirl4786]

Thanks very much

[@elipetrova8347]

Great video! Excellent explanation! I have a question! I had a case with a polypoid lesion with spindel cells, small vessels and a lot of mast cells. The spindel cells were positive for SOX10 and S100 but negative for Melan A. At the same time only in one slide there was a part of a hair follicle and type B melanocytes around it that stained for SOX10, S100 and Melan A. How would you interpret this - neurofibroma or neurotized neavus?

[@ALIWARISVIGHIO87]

Great for students.

[@sameeraansar1343]

Thank you! Could you please do a topic on how to differentiate on cutaneous lymphocytic infiltrate Vs Lymphomas?

[@hayder5391]

Very informative…like👍

[@nisreenfidda6477]

Please make a video for nevi with cytotologic and architectural atypia/ dysplastic nevi

[@norhansaffan2526]

you are amazing

[@SandhyaRamachandran]

Tanq soo much...great one Jerad...keep it up... 1) at 33:17 do we see an intranuclear inclusion in a melanocyte ? 2) Does the feature "symmetry" apply only to shave biopsies as we get most of the lesion... how can we apply it to punch biopsies please?

[@adelh5417]

thank you professor. can you tell me about uvea melanoma

[@masoudmireskandari3178]

Thank you so much for this excellent video. I have two questions: many pathologist comment about the completeness of excision of melanocytic lesions in their reports. Considering the benign nature of the lesions, do you find it necessary? The second questions: do you have a plan for making a video about the application and usefulness of immunohistochemistry in melanocytic lesions?

[@JMGardnerMD]

Thanks! 1. Yes, I usually do give that info by saying "not extending to section edges" or "transected (margins positive)" on the biopsy report for most melanocytic lesions. Most of the dermatologists I work with prefer to know. But I'm also happy to leave that information off if requested, as well. For BCC and SCC I do not routinely include "margin" status. Here's a paper we wrote that explains why: www.ncbi.nlm.nih.gov/pubmed/27116089. 2. Yes I plan to cover melanocytic immunostains in a video in the near future.

[@kinludovico]

Thank you Dr. Gardner, excellent start to approach the melanocytic lesions :). I have a question: is the term dysplasia designed to describe the abnormal architecture and the term atypia to describe the abnormal cellularity? i.e. does the problematic "dysplastic nevus" consist of only architectural dysplasia or both architectural dysplasia and cellular atypia, or should we simply forget this terminology? kind regards.

[@JMGardnerMD]

Haha. You got right to the tough questions! I will do a video about this topic in near future (although I'm already dreading arguments from various factions). In short, I think that dysplastic nevus is supposed to have certain architectural features and cytologic atypia. I can find at least focal cytologic "atypia" in a wide variety of different nevi; it's very subjective. Severe cytologic atypia concerns me much more, of course. I use the term "dysplastic nevus" because I was trained that way and the derms I work with understand the term, but I do not believe that most of these lesions are truly dysplasia or malignant precursors any more than any other nevus. I certainly understand why some people are adamantly against the term, but I don't expect that it will disappear anytime in my career, as it has already been entrenched for so long.

[@SandhyaRamachandran]

@@JMGardnerMD Thank you Jerad! for ur excellent videos..I watch n re-watch them..they are absolute pearls! I heard in Dr McKee's talk:"... If (architectural atypia but)no cytologic atypia, then called a Clarke’s nevus (WHO) ..Sometimes, a b9 nevus can have a host response, WHO calls that also as a Clarke’s nevus..." :) So Clarke's nevus adds to the confusion ; does it bridge a b9 nevus & a dysplastic one ? and can we lump it as a b9 nevus? I'm already hvng to deal with Active nevus too... :):)

[@JMGardnerMD]

Also check out my videos on melanoma basics ( kzbin.info/www/bejne/bn-Teo2QpatrqtU ) and melanocytic immunohistochemistry ( kzbin.info/www/bejne/gKqxn55jgsmJp6c ). And be sure to read the disclaimer in the video description above.

[@jennah19]

thank you for posting these, so helpful!

[@nazarhussain8510]

Exçellent vidèo thank you

[@mohamedjassim731]

Very useful content Dr.Jerad. It was like a treat for me as a resident. Appreciative.. Good Job. Thank yo so so much. Expecting more regarding basics. My doubt is that .. 1) Is that necessary to comment on report about the involvment of inked margin by nevi. Is there any significance? 2) What is the significance of Symmetry? If we find asymmetry for example? What should we think of?

[@JMGardnerMD]

1. Yes, I usually comment if nevus involves edge of biopsy or not. I don’t think it is required, and some Dermpaths do not comment on this. I do because most of the dermatologists I work with want to know this info. 2. Asymmetry is a clue for possible melanoma, melanoma arising in nevus, or two different melanocytic lesions colliding with one another. I have seen many benign nevi that had asymmetry but I like to stop and look closer when I see this feature to make sure I’m not missing melanoma.

[@christoferberganza1316]

Jerad can you add macroscopic view to your presentations? 👀

[@goharrehman7710]

please do a lecture about stains

[@SandhyaRamachandran]

u hv explained beautifully that the melanocyte produces but the keratinocyte stores the melanin pigment. This applies to keratinocytes in the epidermis. In the pigmented nevus esp at 37:57 the deeply pigmented cells at the tips of the rete .. are they keratinocytes or melanocytes ..please.. at 1:08:24 they are explained but those are huge melanocytes..

[@sirik3639]

Thanks a lot sir.. you taught me so much today that i havent learnt in my pg..no words..! could you please teach us bullous lesions too..?

[@JMGardnerMD]

Glad I could help! I’ll try to cover bullous sometime in future.

[@tonychen4298]

How can I differentiate between a neurofibromas vs a nevus with extensive neurotization, assuming that a ”conventional“ area of nevus is not obviously present? Does the presence of mast cells sway you towards a neurofibroma? Or can you see mast cells in neurotised naevi too? Thanks

[@JMGardnerMD]

Firstly, they are both benign so the distinction is rarely of clinical importance. But even in extensively neurotized nevi, there are still some round or epithelioid nevoid melanocytes (often in superficial dermis) that can be seen on H&E. If I don’t see any of those, then I call it neurofibroma. If I really want to know, I do MART-1, although I have seen loss of expression in the neurotized areas of nevi. Mast cells can be seen in both entities so I don’t think of them as a specific feature of neurofibroma.

[@virginialaborda7566]

Me gustaría y necesito esta información en español. Por favor.

[@user-wj6bj4xr4p]

Doc, could you please refer us to other channels for nondermal pathology sections?

[@JMGardnerMD]

my playlist of other pathology KZbin & Kiko video channels: kikoxp.com/posts/15619

[@user-wj6bj4xr4p]

@@JMGardnerMD So Thankful Dr. Gardner

[@goofymania84]

I had got my results back from having a biopsy of my mole under my left foot and it turned out to be junctional nevus as non cancerous but that medical term is only for children and young adult and I'm only 37 years old and I'm an African American. I had found out that junctional is only for lighter skin complexion and I'm brown skinned . I'm hoping that I wasn't misdiagnosed as benign when that term is only for young adult range. I've looked on Google for research

[@JMGardnerMD]

I see junctional nevus in middle aged and even elderly adults all the time. So that alone is not a worrisome diagnosis. If you are worried about your diagnosis you could always request having the case sent to a dermatopathology expert for a second opinion. Please discuss with your dermatologist so they can help you decide on whether or not that would be helpful in your situation. Best wishes for health and healing.

[@zainabnasir8943]

So melanocytes that are deeper are more mature , right ?

[@mikexue5104]

which hospital has the most fame to remove congenital nevus in the world?

[@drngpf1]

Thank you so much for a great video.. do you believe in IHC stains eg. Ki67 or HMB45 to differentiate between benign nevus and melanoma? ☺

[@DoctorSpicy]

Janice histopathology Ki 67 always.

[@JMGardnerMD]

I occasionally use Ki-67/MART-1 double label immunostain in some difficult cases where there are atypical features and a significant amount of dermal melanocytes are present. When very low or very high, it can sometimes provide some useful additional information to take into account when deciding on the final diagnosis. But I essentially never use the Ki-67 result by itself to decide if a lesion is nevus versus melanoma. I have seen HMB-45 used to help assess maturation pattern, but I personally find it challenging to interpret in most cases and thus of relatively limited value for my practice. Again, others may have very different opinions or practice patterns from me, and that's ok. I'm just sharing how I currently think about these things.

[@drngpf1]

thank you for your explanation and your approach in dealing with melanocytic lesion. looking forward your coming video.

[@abantikakonar6480]

Concised lippincotts book on skin