00:01
Our topic now brings
us into nevi.
00:04
So with nevi, what we’ll do is
first define what a nevus is.
00:08
Nevus is a cluster of melanocytes.
00:11
Once again, a nevus is a
cluster of melanocytes.
00:15
If it’s cluster of melanocytes, then guess
what color it’s going to give your skin.
00:19
Well, depending as to location.
00:22
By that I mean, if it’s
in the epidermis more so,
then it will give your skin a pigmented
or brownish type of appearance.
00:29
But if you have a cluster of melanocytes
that is deeper down in your dermis,
well, think about that please.
00:34
If your melanocytes are
deeper down in the dermis,
how was that then going to give you --
or the presentation of such
significant hyperpigmentation?
And really, it doesn’t.
00:44
But at this point, all I’m going to
introduce you to is the definition,
which is cluster of melanocytes.
00:51
We’ll first walk through
our benign nevi.
00:53
And once we walk through
our benign nevi,
then what may then happen to the nucleus is
the fact that it may then become atypical.
01:01
And if you have an atypical
or dysplastic nevi,
guess where we're headed?
Our third,
well not really third,
but another type of skin
cancer known as your melanoma
that obviously that being
extremely common in the U.S.
01:16
There are two categories.
01:17
The common nevus which is
symmetric, uniform without atypia.
01:22
What does that mean to you?
Benign, benign, benign,
benign, benign, right?
We’ve had the discussion
plenty in neoplasia.
01:28
Without increased concern.
01:32
If on the other end of the spectrum,
we have a nevus that is dysplastic.
01:37
Irregular shape,
pigmentation with
atypical cytology.
01:44
Possibly preneoplastic,
hence, it requires and
mandates and warrants
proper followup to make sure that
your patient doesn’t go into melanoma.
01:53
Is this understood?
Lay down the foundation first for nevi,
it is only then that you’re permitted
to move on to our various steps to nevi
and then eventually
into our melanomas.
02:07
Benign nevus,
junctional is our
first description.
02:12
I’m not going to give you a
picture for every single one.
02:14
Where it’s necessary, I’m going
to give you a high-yield picture.
02:17
But at this point, I would like for
you to think about the definition
or the concept of junctional.
02:23
Where are you right now?
You’re on the skin.
02:25
And so therefore, the major
junction that you’re thinking about
is your dermoepidermal junction.
02:31
So at that particular
junction, at the DEJ,
there is a macular lesion.
02:36
Macular, what does
that mean to you?
You can’t really feel it.
02:39
Composed of?
Well, what does a nevus mean?
A cluster of melanocytes.
02:43
There you go.
02:44
And so therefore, you’re going to find
a hyperpigmented type of presentation.
02:51
Compound.
02:52
Now as we move from
the junctional,
we’re going to start talking about
nevi or clusters of melanocytes
which are then going to invade deeper.
03:00
But keep in mind, that we still are
not referring to dysplastic nevus.
03:05
Not yet.
03:06
So compound nevus will be a
papular lesion, once again,
which now is going to extend
further down into dermis.
03:15
And finally we are in only
the dermis,
intradermal.
03:20
So if we think intradermal nevus,
we were talking about these
clusters of melanocytes
that are now strictly
in the dermis.
03:28
Therefore now, this particular papule
minimally if at all pigmented.
03:32
Is that clear?
Why?
Because the cluster of melanocytes is not
as superficial as it was with intradermal.
03:39
I would like for you to create a story for
yourself as we’re moving from the junction
into the compound, from the
compound strictly into the dermal.
03:49
Is this clear?
All referring to nevi of different types
and clusters of your melanocytes.
03:58
If you take a look at
this intradermal nevus,
granted, it looks a little
pigmented, but truly,
In terms of its color,
it really is an extension of the
natural complexion of your patient.
04:14
Where is the cluster
of nevi here?
Strictly in the dermis, intradermal.
04:22
Here, we take a look
at dysplastic nevus.
04:24
Usually sporadic.
04:26
And how dangerous is dysplastic?
Really dangerous.
04:29
Dysplastic nevus syndrome,
inherited disorder.
04:33
D-N-S, dysplastic
nevus syndrome.
04:37
You must think of it as
being premalignant thus
warrants proper follow up because
you’re worried about melanoma.
04:47
With dysplastic, here is
your A through E criteria.
04:51
A, B, C, D, E criteria
for being concerned
or being highly concerned
about neoplastic changes.
05:02
If you’re able to meet some of the criteria
here or A through E criteria for a nevus,
you’re that much
closer to melanoma.
05:12
I’ll show you.
05:14
Asymmetry.
05:15
Border irregularity.
05:16
C – color variegated, many
colors within the same nevus.
05:20
Diameter, memorize greater
than 6 millimeters
of the nevus.
05:26
And evolution.
05:29
If A through E criteria had been met,
you’re increasing
risk for melanoma.
05:38
Dysplastic nevus.
05:40
If you were to then take a look at this,
it’s utter chaos that is taking place.
05:44
It’s difficult to actually
identify the epidermis or dermis.
05:48
And as far as the cells are
concerned, melanocytes,
they’re undergoing
atypical changes.
05:54
You see this here on your
histologic section.
06:00
Now with nevi, differential diagnoses:
We’ll talk about melanoma.
06:05
As soon as you hear about seborrheic
keratosis, you’re thinking about what?
Stuck on appearance, older
patient, autosomal dominant,
slowly growing, more
likely containing pigment.
06:14
A cherry hemangioma, this is a small
dome shaped bright red papule.
06:20
Increased number with age and
remember that it’s permanent,
very common and
extremely benign.
06:25
A cherry hemangioma, it
looks like a cherry.
06:28
Think of a cherry for me and that’s exactly
what a cherry hemangioma looks like.
06:33
These are differentials
for nevi.
06:38
Here, we’ll take a look at
a clinical benign nevus.
06:42
This is what’s known
as a junctional nevus.
06:46
A junctional nevus would
be located where?
Clusters of your melanocytes between
the dermoepidermal junction.
06:53
And therefore, because it’s a
little bit more superficial,
you will then give this presentation
of being, well, symmetrical.
07:02
The border is nice
and well demarcated.
07:05
The color, homogeneously dark.
07:09
The diameter, less
than 6 millimeters.
07:11
Trust me on that.
07:13
And there is no elevation.
07:14
This is a macule.
07:15
What did I just walk you through?
A, B, C, D, E
versus
clinically atypical nevus.
07:26
Start with A, asymmetrical.
07:29
B, irregular border.
07:33
I want you to compare here
on the right to your left.
07:36
C,
look at the central
portion of the nevus.
07:39
It is dark.
07:41
The peripheral
portion is lighter.
07:43
So different colors.
07:45
D,
the diameter is greater than 6 millimeters
compared to diameter here on your right to
the one of junctional nevus on the left.
07:54
E,
it’s elevated.
07:58
Macule on the left and elevated
type of lesion on the right.
08:03
You see something like this in A through E
or suspects or fulfills the
criteria of A, B, C, D, E,
You’re worried about what?
Going on to melanoma.