ACQUIRED Pigmented Lesions

Question 1

Which is this lesion? 
Small (<5 mm) welldemarcated
light brown
macules
Sites: sun-exposed skin

Answer 1

Ephelides

Freckles

Question 2

Which is this lesion?
Hairy, light brown
macule/patch with
a papular verrucous
surface
Sites: trunk and
shoulders, onset in
teen yr

Answer 2

Becker’s Nevus

Question 3

Which is this lesion?
Symmetrical
hyperpigmentation on
sun-exposed areas of
face (forehead, upper
lip, cheeks, chin)

Answer 3

Melasma

Question 4

Which is this lesion?
Variegated macule/
papule with irregular
distinct melanocytes in
the basal layer
Risk factors: family
history

Answer 4

Atypical Nevus

Dysplastic Nevus

Question 5

Which is this lesion? well circumscribed, round, uniformly pigmented macules/papules <1.5 cm. commin mole.

Answer 5

ACQUIRED NEVOMELANOCYTIC NEVI

Question 6

Which is this lesion? Well-demarcated
brown/black macules
Sites: sun-exposed skin

Answer 6

Solar Lentigo

Liver Spot

Question 7

ACQUIRED NEVOMELANOCYTIC NEVI

Clinical Feature. Average number. and stages

Answer 7

• average number of moles per person: 18-40

* 3 stages of evolution: junctional NMN, compound NMN, and dermal NMN

Question 8

Junctional NMN. Age of Onset

Answer 8

Childhood
Majority progress to
compound nevus

Question 9

Junctional NMN. Clinical Feature

Answer 9

Flat, regularly bordered, uniformly tan-dark

brown, sharply demarcated macule

Question 10

Junctional NMN. Histology

Answer 10

Melanocytes at dermal-epidermal

junction above basement membrane

Question 11

Compound NMN. Age of Onset

Answer 11

Any age

Question 12

Compound NMN. Clinical Feature

Answer 12

Domed, regularly bordered, smooth, round,
tan-dark brown papule
Face, trunk, extremities, scalp
NOT found on palms or soles

Question 13

Compound NMN. Histology

Answer 13

Melanocytes at dermal-epidermal

junction; migration into dermis

Question 14

Dermal NMN.Age of Onset

Answer 14

Adults

Question 15

Dermal NMN. Clinical Feature

Answer 15

Soft, dome-shaped, skin-coloured to tan/
brown papules or nodules
Sites: face, neck

Question 16

Dermal NMN. Histology

Answer 16

Melanocytes exclusively in dermis

Question 17

ANMN Management

Answer 17

new or changing pigmented lesions should be evaluated for atypical features which could indicate a
melanoma
• excisional biopsy should be considered if the lesion demonstrates rapid change, asymmetry, varied
colours, irregular borders and persistent pruritus or bleeding

Question 18

Atypical Nevus

(Dysplastic Nevus) Pathophysiology

Answer 18

Hyperplasia and proliferation
of melanocytes extending
beyond dermal compartment
of the nevus
Often with region of adjacent
nests

Question 19

Atypical Nevus

(Dysplastic Nevus) Epidemiology

Answer 19

>5 atypical nevi increase risk for
melanoma
Numerous dysplastic nevi may
be part of familial atypical mole
and melanoma syndrome

Question 20

Atypical Nevus

(Dysplastic Nevus) Clinical Course and Management

Answer 20

Follow with baseline photographs
for changes
Excisional biopsy if lesion changing
or highly atypical
Close surveillance with whole body
skin examination

Question 21

Ephelides

(Freckles) Pathophysiology

Answer 21

Increased melanin within
basal layer keratinocytes
secondary to sun exposure

Question 22

Ephelides

(Freckles) Epidemiology

Answer 22

Skin phototypes I-II most

commonly

Question 23

Ephelides

(Freckles) Clinical Course and Management

Answer 23

Multiply and darken with sun
exposure, fade in winter
No treatment required
Sunscreen and sun avoidance may
prevent the appearance of new
freckles

Question 24

Solar Lentigo

(Liver Spot) Pathophysiology

Answer 24

Benign melanocytic
proliferation in dermalepidermal
junction due to
chronic sun exposure

Question 25

Solar Lentigo | (Liver Spot) Epidemiology

Answer 25

Most common in Caucasians >40 yr Skin phototypes I-III most commonly

Question 26

Solar Lentigo | (Liver Spot) Clinical Course and Management

Answer 26

Laser therapy, shave excisions, | cryotherapy

Question 27

Becker’s Nevus Pathophysiology

Answer 27

Pigmented hamartoma with increased melanin in basal cells

Question 28

Becker’s Nevus Epidemiology

Answer 28

M>F Often becomes noticeable at puberty

Question 29

Becker’s Nevus Clinical Course and Management

Answer 29

Hair growth follows onset of pigmentation Cosmetic management (usually too large to remove)

Question 30

Melasma Pathophysiology

Answer 30

Increase in number and activity of melanocytes Associated with estrogen and progesterone

Question 31

Melasma Epidemiology

Answer 31

``` F>M Common in pregnancy and women taking OCP or HRT Risk factors: sun exposure, dark skin tone Can occur with mild endocrine disturbances, antiepileptic medications and other photosensitizing drugs ```

Question 32

Melasma Clinical Course and Management

Answer 32

``` Often fades over several mo after stopping hormone treatment or delivering baby Treatment: hydroquinone, azelaic acid, retinoic acid, topical steroid, combination creams, destructive modalities (chemical peels, laser treatment), camouflage make-up, sunscreen, sun avoidance ```