Benign pigmented lesions (Seborrheic keratosis & Ephelis) Flashcards
What population is sebhorrheic keratosis common in?
older people
What is seborrheic keratosis?
acquired benign proliferation of epidermal basal cells
Cause of sebhorrheic keratosis?
Unknown.
Positive correlation with sun exposure
What kind of mutation is asosciated with sebhorrheic keratosis?
somatic mutations in the FGFR3
Does sebhorrheic keratosis occur in the mouth?
does NOT occur in the mouth
Where does sebhorrheic keratosis develop?
skin of the face, trunk and extremities
How do sebhorrheic keratosis lesions appear?
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.
What is dermatosis papulos nigra?
seborrheic keratosis that occurs in 30% of blacks
What is observed in the histology of the acanthotic form of sebhorrheic keratosis?
Considerable acanthosis
Surface hyperkeratosis
Numerous pseudocysts
Where does the epidermal proliferation extend in the histopathology of sebhorrheic keratosis?
Extends upwards above the normal epidermal surface
What are the pseudocysts in the histopathology of sebhorrheic keratosis?
Keratin filled invaginations
How do surrounding epithelial cells appear in the histopathology of sebhorrheic keratosis?
Basaloid in appearance
Is sebhorrheic keratosis often removed?
seldom removed unless for aesthetic reason
How are sebhorrheic keratosis lesions removed?
liquid nitrogen or simple curettage
Is there malignant potential of sebhorrheic keratosis?
No malignant potential
What is Lesar-Trelat sign?
Sudden appearance of numerous sebhorrheic keratosis with pruritis that has been associated with internal malignancy
What is ephelis?
Common small hyperpigmented macule of the skin.
Represents a region of increased melanin production not a local increase in number of melanocytes.
In what population is ephelis most observed and where on the body?
Seen most often on the face, arms and back of fair skinned, blue-eyed, red or light blond haired persons
When does ephelis become noticeable?
first decade of life
Is there a sex association with ephelis?
No sex predilection
How does each macule in ephelis appear?
Each individual macule is round or oval and typically remains less than 3mm in diameter.
Uniform light brown coloration, color intensifies after sun exposure
How do ephelis spots compare to lentigo simplex?Melanocytic nevus?
Not as dark as lentigo simplex
Never elevated like melanocytic nevus
What is the histopahtology of ephelis composed of?
stratified squamous epithelium with abundant melanin deposition in the basal cell layer
NORMAL melanocytes number or somewhat reduced
How do the rete ridges appear in ephelis in comparison to lentigo simplex?
Rete ridges are not elongated like in lentigo simplex
Tx for ephelides?
No tx necessary
Use of suncreen can prevent appearance of new freckles
What is seborrheic keratosis that occurs in 30% of blacks
dermatosis papulos nigra
