9a - Nevi & Malignant Melanoma Part 1

Question 1

What is a nevus?

Answer 1

Mole

Question 2

What are the ABCDEs of examining a mole?

Answer 2

Asymmetry
Border irregularity
Color variation
Diameter (size/enlargement)
Evolving (change in size, shape, color or a new lesion)

Question 3

Melanocytic nevus are also known as:

Answer 3

Moles

Question 4

What are melanocytic nevi?

Answer 4

Benign tumors composed of nevus cells derived from melanocytes

Question 5

Incidence and distribution of melanocytic nevus?

Answer 5

Both sexes
Become larger during 50’s and 60’s

Anywhere, but typically found in sun exposed areas

Question 6

Morphology of melanocytic nevus

Answer 6

Sharply circumscribed
Uniform colored papules or macules
Irregular surface with or without hair
Single or multiple 
Size varies greatly

Question 7

Dx of melanocytic nevus?

Answer 7

Appearance and history

Bx reveals nest of nevus cells

Bx any lesion if change in appearance

Question 8

Txt for melanocytic nevus

Answer 8

Follow-up for ABCDE changes

If >100 nevi, follow at 6-12 month intervals

Surgical excision for shady shit

Question 9

What are the three main subtypes of common (acquired) nevi?

Answer 9

Junction nevi
Compound nevi
Dermal nevi

Progress over years, affected by hormones and sun

Question 10

Slide 8

Answer 10

Illustration of development of nevi over the years

Question 11

Junctional nevi

Answer 11

Nest in the epidermis and epidermis-dermal junction

Flat or slightly elevated

Light brown to brown-black with uniform pigmentation

Size <0.5-0.8cm

Most common in childhood - may develop into compound nevi after childhood

Question 12

Compound nevi

Answer 12

Nevus with nest into the upper dermis

Slightly elevated to dome-shaped, smooth or warty surface, with or without hair

Uniformly round, oval, and symmetric

White periphery = “halo nevus”

Question 13

Dermal nevi

Answer 13

All nevus cells in dermis, sometimes in fat cells

Dome-shaped (MC), verrucous, pedunculated, sessile

Skin colored to brown-black with hair, become lighter with age

Common in grown-ups

Question 14

What are congenital melanocytic nevi?

Answer 14

Found at birth - 1-6% of all newborns

Vary in size from <1cm to >20cm

Most grow proportionally with child

Greater risk of malignant transformation if >5 BSA or >20cm

Question 15

Management of congenital melanocytic nevi?

Answer 15

Small? Leave alone

Medium? Remove after puberty

Large? Increased incidence of MM; even with removal, 2-3% overall MM risk

Question 16

What is nevus spilus?

Answer 16

AKA “speckled lentiginous nevus”

MC in adolescence

Hairless, oval or irregularly-shaped brown macule

Dotted with darker brown to black papular spots

ANYWHERE, not related to sun exposure

Txt - nothing

Question 17

What is Becker’s nevus?

Answer 17

Either a brown macule, a patch of hair, or both (NO nevus cells) (but it’s still called a nevus….)

Question 18

Where is Becker’s nevus found?

Answer 18

MC’ly unilateral upper back, shoulder, upper arm, submammary

Question 19

What is Becker’s nevus syndrome?

Answer 19

Presence of BN plus associated with ipsilateral breast or limp hypoplasia, scoliosis, spina bifida occulta

Question 20

Txt for Becker’s Nevus?

Answer 20

Usually too large to excise

Hair may be shaved or permanently removed

Laser tx for removal of hair and pigmentation

Question 21

What is the Halo Nevus?

Answer 21

Compound or dermal nevus that develops a white border

MC in adolescence

May herald onset of vitiligo

Question 22

Morphology of Halo Nevus?

Answer 22

One or more hypopigmented to white lesions that contain a central red, brown, or black nevus

No melanocytes in the halo

Nevus regresses and pigment returns (occurs over a decade or more)

Question 23

Where are Halo Nevi most commonly found?

Answer 23

On the trunk

*never on the palms / soles

Question 24

Txt for Halo Nevi?

Answer 24

Teens - none needed (tho parents may push for excision)

Adults - Wood’s lamp - look for blue vitiligo - bx if suspect MM

Question 25

What are Mongolian Spots?

Answer 25

Blue-black lesions - dermal melanocytes (more flattened)

Migratory arrest (unable to make epidermis) before birth

Question 26

Where are Mongolian Spots found?

Answer 26

Mongolia

Question 27

Ok really, where are Mongolian spots found?

Answer 27

MC’ly in scalp and pre-sacral area

Backs of hands

Face/trunk in dermatomal pattern

Question 28

What is the Tyndall Effect?

Answer 28

What causes the blue-black appearance of Mongolian spot lesions

Question 29

Txt for Mongolian spots?

Answer 29

None - usually fades during first few years of life

Question 30

What is Nevus of Ota?

Answer 30

Blue-black pigmentation in 1st-2nd branch of trigeminal nerve

Affects the sclera, conjunctiva, and skin around the eye (no visual changes)

They darken over time

Txt? Lasers to lighten the lesion, monitor for glaucoma

Question 31

What is a Spitz nevus?

Answer 31

AKA benign juvenile melanoma

MC in kids, on the head, neck, and lower extremities

Hairless, red or reddish-brown dome-shaped papules / nodules < 1.5cm, often appearing suddenly

Txt? Remove -> path

Question 32

What is a blue nevus?

Answer 32

Slightly elevated, round, regular nevus

Typically <5mm

Large amount of pigment in dermis

MC on extremities and dorsum of hands

Question 33

Blue nevus is often confused with

Answer 33

malignant melanoma

Blue nevus stays the same

Question 34

Txt of blue nevus?

Answer 34

Removal for patient piece of mind / cosmetic purposes

Question 35

What is labial melanotic macule?

Answer 35

Brown-black macules on lower lip

MC’ly in young adult women

Resembles freckles, but no change with sun exposure

Benign

Txt with cryo or lasers if desired

Question 36

How does a penguin build its house?

Answer 36

Igloos it together