9b - Nevi & Malignant Melanoma Part 2

Question 1

When do dysplastic (atypical) nevi or “clark nevi” typically appear?

Answer 1

Near puberty and the continue to develop past the 4th decade

Question 2

Morphology of dysplastic/atypical/Clark nevus?

Answer 2

Usually >5mm, either flat or flat with a raised center (“fried egg”)

Dark or irregularly-pigmented (shades of brown and pink)

Irregular or indistinct borders

Question 3

Where are dyplastic nevi found?

Answer 3

Most commonly the back
Upper and lower limbs
Sun-protected areas (breast/scalp/buttocks/groin)

Question 4

Dx of dysplastic nevus?

Answer 4

At least three of the following:

• diameter >5mm
• ill-defined borders
• irregular margin
• varying shades in lesion
• presence of papular and macular components

Question 5

Txt of dysplastic nevus?

Answer 5

If suspicious (hey, that’s profiling!) do an excisional bx with margins

Pt education, sun avoidance

F/U at least Q 6 mos

Suggest screening family

Consider referral for ophthalmologic exams

Question 6

Median age for dx of MM?

Median age for death from MM?

Answer 6

57

67

Question 7

Who is most at risk for MM?

Answer 7

White dudes

Question 8

Risk factors for MM (greatly increased risk)

Answer 8

1. Personal hx of atypical moles, Fhx of melanoma, and > 75-100 moles
2. Previous nonmelanoma skin CA
3. Congenital nevus (giant, 20cm)
4. Immunosuppression
5. Hx of melanoma

Question 9

Risk factors for malignant melanoma (moderate)

Answer 9

1. Clinically atypical nevi (2-9) - no fhx of melanoma or sporadic nevi
2. Large number of nevi
3. Chronic tanning
4. Repeated blistering sunburns
5. Freckling
6. Fair skin
7. Red or blond hair

Question 10

UV exposure risks for MM?

Answer 10

Acute episodic exposures LIKELY MORE RISK than constant occupational exposure

“Snow bird spots”

Question 11

Morphology of MM:

Answer 11

Look for ABCDE’s:
Asymmetry
Border irregularity
Color variation
Diameter enlargement
Evolution (change)

Question 12

Distribution of MM:

Answer 12

Anywhere

Back is MC for men

Arms and legs MC for women

Mucosal MM more common in non-white populations

Question 13

Slide 22

Answer 13

Helpful illustrations of benign vs malignant

Question 14

Dx of MM:

Answer 14

Bx

Dermascopy can aid in ID’ing “look-alikes” (requires training and practice)

Question 15

Management of MM:

Answer 15

Excision or punch - NO SHAVE

Close follow up - Q 3-4 mos x 1 yr, then q 6 mos thereafter

Question 16

Prognosis of MM:

Answer 16

Directly related to tumor size and depth of invasion - early detection = imperative

If metastatic -> grim prognosis

Breslow - most important determinant of prognosis - checks depth

Clark - depth by anatomic site

Question 17

What are the four histopathologic types of MM?

Answer 17

1. Superficial spreading (MC)
2. Nodular
3. Lentigo maligna
4. Acral-lentiginous (least common)

Question 18

What is the MC type of melanoma?

Answer 18

Superficial spreading melanoma (SSM)

Question 19

SSM most commonly occurs at what age?

Answer 19

30’s or 40’s

Question 20

SSM most commonly occurs where?

Answer 20

Upper back

Legs (women)

Question 21

Morphology of SSM

Answer 21

Irregular, asymmetric borders

Begins as flat or elevated brown lesion

Hallmark is haphazard combo of many colors (more so with time)

Nodules appear when lesion >2.5 cm

Question 22

What is nodular melanoma?

Answer 22

Completely vertical growth phase (no radial growth)

Can occur anywhere

50 yr old males

Question 23

Morphology of nodular melanoma

Answer 23

Most commonly dark brown, red-brown, or red-black

Dome-shaped, polypoid or pedunculated

Rapid growth, then ulcerates and bleeds

Most commonly misdiagnosed type

Question 24

What is lentigo maligna melanoma?

Answer 24

Lateral growth phase lesion

65 y/o’s

MC’ly face - also neck, arms (sun damage)

Slow growth (5-20 yrs)

Question 25

Morphology of lentigo maligna melanoma

Answer 25

Complex pattern due to repetition of evolution and regression

Brown-black macular pigmentation

Raised blue-black nodules

5% risk of becoming invasive

Question 26

What is acral-lentiginous MM?

Answer 26

Palms, soles, terminal phalanges, and mucous membranes

Same colors and tendency to remain flat (like lentigo maligna)

Hutchinson’s sign - under nail plate -> sudden appearance of pigment at proximal nailfold

Very poor prognosis

The MC form of MM for dark-skinned people

Question 27

Early stage MM is difficult to dx in:

Answer 27

Patients with darker skin

Hence poorer overall prognosis usually with darker skinned people

Question 28

In white people, 90% of MM is found on:

Answer 28

Sun-exposed areas

What does this tell us? If you’re white, you can PREVENT this shit with sunblock! Don’t scoff at it.

Question 29

In dark skinned people, where is MM commonly found?

Answer 29

The foot

Also, mucosal surfaces

Question 30

Modified ABCDEF for dark skinned patients:

Answer 30

Age (5th/6th decades)
Brown or black band
Change - recent, sudden, or rapid development
Digit - most commonly involved
Extension of brown pigment onto cuticle or where a hangnail may develop
Family hx or personal hx of unusual moles or MM

Question 31

Slide 64

Answer 31

Illustration of progression of MM

Question 32

Horizontal growth phase for MM:

Answer 32

Better prognosis

Once a lesion begins vertical growth prognosis worsens (mets is rapid after vertical growth begins)

Question 33

Depth of invasion based on Clark level is an important predictor of:

Answer 33

5-yr survival

Level I - epidermis - 98%
Level II - papillary dermis
Level III - fill papillary dermis
Level IV - reticular dermis
Level V - SubQ - 44%

Question 34

What is the MOST important histologic determinant of prognosis in MM?

Answer 34

Breslow microstage

Depth in mm at thickest point

Reported as “Breslow Level #mm”

Question 35

In lesions >1mm thick, what is the most important prognostic factor?

Answer 35

Extent of lymph node involvement

Question 36

Did you hear about the restaurant on the moon?

Answer 36

Great food, no atmosphere