Melanocytic Lesions - part I Flashcards
melanocytic lesions
- ephelis
- actinic lentigo
- melanotic macule
- acquired melanocytic nevus
- congenital melanocytic nevus
- blue nevus
- melanoma
ephelis
freckles
clinical features of ephelis
- more pronounced with sun exposure
- light/medium brown macules of skin
- round or oval 3 mm or less
- sharply demarcated
- fair-skinned, blue eyes, red or blonde hair
treatment for ephelis
none indicated
prognosis of ephelis
- identify skin type that may be more susceptible to UV damage
- SPF products should be used
actinic lentigo
hallmark of UV damaged skin, “age spots” or “liver spots”
where does actinic lentigo appear?
on sun-exposed skin
clinical features of actinic lentigo
- completely macular
- often multiple (may coalesce)
- uniformly pigmented brown to tan
- well-demarcated irregular borders
treatment for actinic lentigo
- none indicated unless for esthetic reasons
2. SPF products suggested
what can be done to treat actinic lentigo
- cryotherapy
- laser ablation
- intense pulsed light
- chemical peel
- topicals
what causes melanotic macule
unknown etiology but similar lesions associated with systemic conditions, medications and genetic disorders
clinical features of melanotic macule
- maximum dimension achieved rapidly then remains constant
- round to oval 7 mm or less
- uniformly tan to dark brown
- demarcated margins
is melanotic macule common?
yes, common and harmless
T/F: melanotic macule occurs due to sun exposure
false, not dependent on sun exposure
T/F: melanotic macule has a female predilection
true
what age group is affected by melanotic macule?
average age 43 but broad age range
what is the most common location for melanotic macule?
lower lip vermilion zone
histopathologic features of melanotic macule
- increased melanin pigmentation along basal epithelial layer
- may show melanin incontinence
- normal stratified squamous epithelium
treatment for melanotic macule
none indicated unless for esthetics
when would an excisional biopsy be indicated for a melanotic macule?
if recent onset, large size, irregular pigmentation, unknown duration, recent enlargement
T/F: melanotic macule are malignant
false, considered benign
acquired melanocytic nevus
mole
most common of all human “tumors”
acquired melanocytic nevus
clinical features of acquired melanocytic nevus
- gradually involute with age
- macules or papules (flat or raised)
- sharply demarcated
- brown, black, tan, skin-colored
- less than 6 mm
- hair
when does acquired melanocytic nevus develop?
during childhood through ~4th decade
acquired melanocytic nevus is common in what race?
Caucasians
where are acquired melanocytic nevus most commonly found?
head and neck
T/F: most acquired melanocytic nevi are above the waist
true
sites of acquired melanocytic nevus in the oral cavity
hard palate or attached gingiva, but potentially any site can be affected
stage of acquired melanocytic nevus depends on what?
depends on location of nevus cells microscopically
stages associated with evolution of acquired melanocytic nevus
- junctional
- compound
- intradermal (intramucosal)
junctional stage of acquired melanocytic nevus
nevus cells only in epithelium/epidermis
compound stage of acquired melanocytic nevus
nevus cells in epithelium/epidermis and CT
intradermal stage of acquired melanocytic nevus
nevus cells only in CT
no treatment is indicated for cutaneous acquired melanocytic nevus unless what?
unless 1. chronically irritated
- an esthetic concern
- changes in size or color
what is advised of all unexplained pigmented oral lesions?
excisional biopsy
what can resemble oral mucosal nevi?
early melanoma
what is the risk of malignant transformation from an individual cutaneous nevus to melanoma?
low
is oral nevi currently considered an increased risk for melanoma?
no
congenital melanocytic nevus
- present at birth
2. very large “bathing trunk nevus,” “garment nevus”
sites for congenital melanocytic nevus
- trunk and extremities
2. 15% H&N
small congenital melanocytic nevus resembles what?
acquired melanocytic nevi
what is the difference between congenital melanocytic nevus and acquired melanocytic nevi?
tend to be larger (greater than 6 mm), darker and hairier
clinical features of congenital melanocytic nevus
hypertrichosis (excess hair)
how are congenital melanocytic nevus classified?
by projected adult size
small congenital melanocytic nevus
<1.5 cm
medium congenital melanocytic nevus
up to 20 cm
large congenital melanocytic nevus
greater than or equal to 20 cm
treatment for congenital melanocytic nevus
excise for esthetic reasons
how would you get rid of the congenital melanocytic nevus?
- dermabrasion
- chemical peel
- laser
- cryotherapy
- partial surgical excision
what is the percent risk of malignant transformation for congenital melanocytic nevus?
~1% for small
what is the percent risk of large congenital melanocytic nevus to transform to melanoma?
2-3%
what should be done after treating congenital melanocytic nevus?
close clinical follow-up
cutaneous sites for blue nevus
hands, feet, scalp, face
mucosal sites for blue nevus
mucosal sites, esp. oral and conjunctival
why is the blue nevus blue?
bluish or blue-gray due to the depth of melanin pigment (Tyndall effect)
T/F: blue nevus has a male predilection
false, female
who can have a blue nevus?
children, young adults
clinical features of blue nevus
- less than 1 cm
2. macule or papule
what is the most common oral site of blue nevus?
palate
histopathologic features of blue nevus
- elongated dendritic melanocytes in CT
- abundant melanin pigment
- no atypia
treatment of blue nevus
conservative excision
prognosis of blue nevus
excellent
is recurrence of blue nevus common?
no, it’s rare
is malignant transformation of blue nevus common?
no, it’s rate but reported
melanoma
malignancy of melanocytic differentiation
what is the third most common skin cancer?
melanoma
melanoma makes up what percent of all skin cancers?
5%
what percent of skin cancer deaths are due to melanoma?
75%
T/F: the lifetime risk of melanoma is increasing
true
T/F: incidence rate of melanoma is increasing
true
T/F: mortality rate of melanoma is increasing
false, not increasing as much
risk factors for melanoma
- whites esp. fair-skinned
- light hair/eyes
- family history of melanoma (genetic predisposition)
- personal hx of melanoma
- tendency to sunburn/freckle easily
- history of blistering sunburn early in life (acute sun exposure > chronic)
- indoor occupation; outdoor recreation
- hx dysplastic or congenital nevus
- > 100 common nevi
- immunocompromised (organ transplant)
clinical features of melanoma
- 40-70 yo
- female predilection under age 40
- male predilection in older pts
which sex has overall slight predilection of melanoma
male