Benign pigmented lesions (Seborrheic keratosis & Ephelis)

Question 1

What population is sebhorrheic keratosis common in?

Answer 1

older people

Question 2

What is seborrheic keratosis?

Answer 2

acquired benign proliferation of epidermal basal cells

Question 3

Cause of sebhorrheic keratosis?

Answer 3

Unknown.

Positive correlation with sun exposure

Question 4

What kind of mutation is asosciated with sebhorrheic keratosis?

Answer 4

somatic mutations in the FGFR3

Question 5

Does sebhorrheic keratosis occur in the mouth?

Answer 5

does NOT occur in the mouth

Question 6

Where does sebhorrheic keratosis develop?

Answer 6

skin of the face, trunk and extremities

Question 7

How do sebhorrheic keratosis lesions appear?

Answer 7

Usually multiple and begin as small tan/brown macules.

Gradually enlarge and elevate.

End as sharply demarcated plaques. Surfaces may be finely fissured, pitted or verrucous, or smooth.

Question 8

What is dermatosis papulos nigra?

Answer 8

seborrheic keratosis that occurs in 30% of blacks

Question 9

What is observed in the histology of the acanthotic form of sebhorrheic keratosis?

Answer 9

Considerable acanthosis

Surface hyperkeratosis

Numerous pseudocysts

Question 10

Where does the epidermal proliferation extend in the histopathology of sebhorrheic keratosis?

Answer 10

Extends upwards above the normal epidermal surface

Question 11

What are the pseudocysts in the histopathology of sebhorrheic keratosis?

Answer 11

Keratin filled invaginations

Question 12

How do surrounding epithelial cells appear in the histopathology of sebhorrheic keratosis?

Answer 12

Basaloid in appearance

Question 13

Is sebhorrheic keratosis often removed?

Answer 13

seldom removed unless for aesthetic reason

Question 14

How are sebhorrheic keratosis lesions removed?

Answer 14

liquid nitrogen or simple curettage

Question 15

Is there malignant potential of sebhorrheic keratosis?

Answer 15

No malignant potential

Question 16

What is Lesar-Trelat sign?

Answer 16

Sudden appearance of numerous sebhorrheic keratosis with pruritis that has been associated with internal malignancy

Question 17

What is ephelis?

Answer 17

Common small hyperpigmented macule of the skin.

Represents a region of increased melanin production not a local increase in number of melanocytes.

Question 18

In what population is ephelis most observed and where on the body?

Answer 18

Seen most often on the face, arms and back of fair skinned, blue-eyed, red or light blond haired persons

Question 19

When does ephelis become noticeable?

Answer 19

first decade of life

Question 20

Is there a sex association with ephelis?

Answer 20

No sex predilection

Question 21

How does each macule in ephelis appear?

Answer 21

Each individual macule is round or oval and typically remains less than 3mm in diameter.

Uniform light brown coloration, color intensifies after sun exposure

Question 22

How do ephelis spots compare to lentigo simplex?Melanocytic nevus?

Answer 22

Not as dark as lentigo simplex

Never elevated like melanocytic nevus

Question 23

What is the histopahtology of ephelis composed of?

Answer 23

stratified squamous epithelium with abundant melanin deposition in the basal cell layer

NORMAL melanocytes number or somewhat reduced

Question 24

How do the rete ridges appear in ephelis in comparison to lentigo simplex?

Answer 24

Rete ridges are not elongated like in lentigo simplex

Question 25

Tx for ephelides?

Answer 25

No tx necessary

Use of suncreen can prevent appearance of new freckles

Question 26

What is seborrheic keratosis that occurs in 30% of blacks

Answer 26

dermatosis papulos nigra