Melanocytic Dermpath Basics: Benign Nevus

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:

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.

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[annaj]

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

[muthannajabbar]

Dr. Gardner,

Your teaching style is truly special—fun and engaging. Watching your videos is like reading a beautiful novel; I can’t stop until the end! You break down complex topics as effectively as bile salts emulsify lipids in the gut, making dense material easy to mentally digest and understand.

I also love teaching and strive to simplify things for my learners. I’m currently a PGY-3 pathology resident, studying and applying for dermatopathology fellowship, and your videos are the best resources I’ve found. I recently got your Dermpath Survival Guide, and reviewing the same topics in the book right after watching your videos makes learning both fun and beautiful. I can’t thank you enough. For those who love dermpath, this is like getting the pearls of 100 hours signing out with an experienced and generous dermatopathologist, but on your own time of preference! It couldn’t be better.

For fun: This morning, while finishing one of your videos, a co-resident passing by in the corridor recognized your voice instantly and said, “Dr. Jared Gardner! You can always recognize his voice" 😊

Thank you for sharing your gift for teaching. It’s truly priceless!

[acck]

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

[MD.Aidaros]

Dr. Gardner, thank you so much for your amazing efforts. I am falling in love with dermpath because of your videos. Your way of teaching makes learning fun and simple. You are a true blessing for all dermpath students.

[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!

[margaritamunozdetoro]

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!

[ShashidharVenkateshMurthy]

Great teaching Great service to global Pathology ...!

[navodakumarasinghe]

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

[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.

[RaulRodriguez-shvb]

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

[missknowall]

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

[AbdallaAbdein]

Thank you so much Dr Gardner. This is so helpful, you are a truly inspiration to me as an aspiring Dermatopathologist!

[UsamaSajidSyed]

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

[machteldsimpson]

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

[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

[pedromarciano]

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)

[abhijeetwaghmare]

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

[evelyne]

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.

[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!

[vinvinvino]

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