09/09 - Melanocytic Lesions

Question 1

What are ephelis?

Answer 1

• dermatologic term for “freckles”

- “epi” = upon, “helios” = sun

Question 2

What are ephelis coorelated to?

Answer 2

based upon sun exposure; identify skin type that may be more susceptible to UV damage

Question 3

What are actinic lentigo (lentigines)?

Answer 3

common, harmless melanocytic lesions that appear on sun-exposed skin, usually the face and dorsum of the hands; called “age spots” or “liver spots”

Question 4

Describe actinic lentigo (lentigines) lesions.

Answer 4

• completely macular, often multiple
• melanocytic
• don’t wax and wane with sun exposure
• have been there for a long time

Question 5

Where do actinic lentigo (lentigines) lesions usually occur?

Answer 5

on the face and dorsum of the hands

Question 6

Describe a melanotic macule.

Answer 6

• tan to dark brown, uniformly pigmented, demarcated margins

- no change with sun exposure

Question 7

Where do melanotic macules usually occur? What is the possible reason behind them?

Answer 7

• usually on the lip or intraorally (especially palate or attached gingiva)
• could represent post-traumatic melanosis (injury, cut, crush –> increases melanin in that area)

Question 8

Describe the histopathology of a melanotic macule.

Answer 8

• microscopically shows no evidence of nevus cells or increased numbers of basilar melanocytes
• typically has an increased amount of melanin pigment in the basal layer or within melanophages in the superficial connective tissue

Question 9

What is the treatment for a melanotic macule?

Answer 9

• lesions on the vermilion zone of the lip are often excised for cosmetic purposes
• tissue should be submitted for microscopic examination
• intraoral lesions may need to be excised to rule out early melanoma

Question 10

True or false: Nevus cells are related to melanocytes.

Answer 10

true

Question 11

True or false: Acquired melanocytic nevi are uncommon.

Answer 11

FALSE. They are one of the most common lesions.

There is an average of 20/person in Caucasians.

Question 12

When do acquired melanocytic nevi develop?

Answer 12

may develop from the 1st year of life through the 4th decade; often involute (disappear) with aging

Question 13

How are acquired melanocytic nevi classified? What are the 3 groups?

Answer 13

• designated depending on where the collection of nevus cells is located microscopically
• junctional, compound, intradermal

Question 14

Differentiate between the 3 groups of acquired melanocytic nevi.

Answer 14

• JUNCTIONAL: involves only the epithelium; first stage; appears flat and dark in color
• COMPOUND: involves connective tissue and epithelium; second stage; some of the nevus cells begin “dropping off” into the superficial connective tissue; may show elevation clinically
• INTRADERMAL: nevus cells are only in the connective tissue (dermal layer); elevated with variable degree of pigmentation (many are normal skin color); may have coarse hair coming out of it

Question 15

Describe acquired melanocytic nevi histologically.

Answer 15

nests of nevus that have a higher nuclear to cytoplasmic ratio; they produce the melanin pigment

Question 16

Where does oral acquired melanocytic nevi occur?

Answer 16

• infrequently develop in the oral cavity

- usually located on the hard palate or attached gingiva, but potentially could be anywhere

Question 17

What is the recommended treatment for acquired melanocytic nevus lesions?

Answer 17

• no treatment is absolutely necessary

- changes in a nevus or chronic irritation of a nevus would be reasons for excisional biopsy

Question 18

What is the risk of malignant transformation of acquired melanocytic nevus?

Answer 18

risk for individual nevus is about 1 in 1 million

Question 19

How common is congenital melanocytic nevus?

Answer 19

present in 1% of newborns

Question 20

What are the 2 groups of congenital melanocytic nevi? Which is more common?

Answer 20

• designated as “large” and “small”

- small (

Question 21

What is the risk of malignant transformation for congenital melanocytic nevi?

Answer 21

• small = 1%

- large = 15%

Question 22

What is the usual treatment for congenital melanocytic nevi?

Answer 22

• staged excision for large (including skin grafts)

- excision for small (?)

Question 23

Describe the appearance of a blue nevus. Where does it occur?

Answer 23

• bluish or blue-gray lesion less than 1 cm in diameter that usually appears in the 4th decade of life
• on any cutaneous or mucosal site

Question 24

What accounts for the color of a blue nevus?

Answer 24

appears bluish or blue-gray due to the depth of the melanin pigment (Tyndall effect)

Question 25

Describe a blue nevus histologically.

Answer 25

• microscopically, shows a collection of dendritic melanocytes within the connective tissue
• typically the lesional cells contain abundant melanin pigment
• no melanocytic atypica should be seen

Question 26

What is the recommended treatment for blue nevus? Prognosis? Recurrence?

Answer 26

• treatment consists of simple excision
• prognosis is excellent
• recurrence is rare (less than 1 in 1 million transform)

Question 27

What is the 3rd most common skin cancer?

Answer 27

melanoma

risk is 1 in 50 now (the mortality of the disease slightly increased while the incidence drastically increased)

Question 28

What is the most serious form of skin cancer?

Answer 28

melanoma

5% of skin cancers; 65% of deaths due to skin cancer

Question 29

What people are most at risk for melanoma?

Answer 29

• fair skinned, 40-70 years of age
• history of blistering sunburn early in life
• indoor occupation, outdoor recreation
• family history of melanoma
• personal history of melanoma

Question 30

What are the ABCDE’s of melanoma?

Answer 30

Asymmetry
Border irregularity
Color variegation
Diameter greater than 6 mm (size of a pencil eraser)
Evolving (enlarging or changing color)

Question 31

What are the four types of melanoma?

Answer 31

• lentigo maligna melanoma
• superficial spreading melanoma
• nodular melanoma
• acral lentiginous melanoma

Question 32

What is lentigo maligna? Who is most affected?

Answer 32

• essentially melanoma in a purely radial growth phase

- affects older individuals (late 60s-80s) who have a fair complexion

Question 33

Describe a lentigo maligna lesion.

Answer 33

large macular lesion with irregular borders and uneven pigmentation; usually on facial skin

Question 34

Rank the types of melanoma from most common to least common.

Answer 34

superficial spreading melanoma (70%)
nodular melanoma (15%)
acral lentiginous melanoma (8%)
lentigo maligna melanoma (5%)

Question 35

What is lentigo maligna melanoma and how does it differ from lentigo maligna?

Answer 35

• nodularity in previously flat lentigo maligna signals vertical growth
• 15 years before vertical growth phase develops

Question 36

Where can superficial spreading melanoma be found? How does it appear histopathically?

Answer 36

• interscapular area in men, legs of women; 15-20% in the head and neck region
• atypical cells with multinucleation

Question 37

True or false: Melanoma may produce a huge inflammatory response with T cells.

Answer 37

true

Question 38

Describe the appearance of a nodular melanoma lesion.

Answer 38

• appear as rapidly growing lesion
• 33% in the head and neck region
• may be amelanotic (don’t produce melanin and resemble a pyogenic granuloma)
• little, if any, radial growth phase

Question 39

Where is acral lentiginous melanoma found? Describe its appearance.

Answer 39

• affects palms, soles, and oral mucosa

- begins as a darkly pigmented macule with irregular borders

Question 40

What is the most common clinicopathologic type of melanoma in persons of color?

Answer 40

acral lentiginous melanoma

Question 41

What is the most common form of melanoma seen inside the mouth?

Answer 41

acral lentiginous melanoma

Question 42

What is the recommended treatment for melanoma?

Answer 42

• surgical excision
• chemotherapy, radiation therapy, or immunotherapy (for patients at high risk for recurrence)
• size of margins for excision is controversial (1-2 cm margins)
• sentinel node biopsy even in absence of local metastasis (IL-2 is used to control)

Question 43

What is the prognosis for melanoma?

Answer 43

• up to 0.75 mm = 96% 10-year survival
• 0.76-1.69 mm = 89% 10-year survival
• 1.70-3.59 mm = 67% 10-year survival
• 3.60+ mm = 26% 10-year survival