Patho of Skin DSA 2

Question 1

What are fibroepithelial polyps?

Answer 1

soft, flesh colored tumors attached by a stalk.

Question 2

Where are fibroepithelial polyps most often seen?

Answer 2

neck, trunk, face. Often seen in middle-aged ppl

Question 3

What is an epidermal inclusion cyst?

Answer 3

Wall is identical to normal epidermis (stratified squamous epi)

Question 4

What is a Pilar cyst?

Answer 4

resembles follicular epithelium

Question 5

Dermoid cyst?

Answer 5

Wall is similar to epidermis but had multiple skin appendages.

Question 6

where do pilar cysts occur?

Answer 6

in the scalp

Question 7

What is the clinical significance of adnexal tumors?

Answer 7

most are benign; some are locally aggressive

may be part of a genetic phenotype predisposed to develop visceral malignancies (Cowden’s)

Question 8

What is cylindroma?

Answer 8

occur on the scalp and forehead. lesions composed of islands of basaloid cells w/ apocrine or eccrine differentiation.

Question 9

What gene is inactivated in cylindroma?

Answer 9

CYLD

Question 10

What is a trichoepithelioma?

Answer 10

proliferations of basaloid cells that form hair follicle-like structures

Question 11

sebaceous adenoma

Answer 11

lobular proliferations w/ frothy lipid filled cytoplasms.

Question 12

What is a pilomatrixoma?

Answer 12

proliferations of basaloid cells that show hair-like differenctiation. Associated w/ mutations of CTNNB1 gene

Question 13

What is an apocrine carcinoma?

Answer 13

axilla/scalp. exhibit ductal differentiation.

Question 14

What has a stuck on appearance, horny pearls of cysts, sign of leser-trelat?

Answer 14

seborrheic keratosis

Question 15

What is Leser-trelat?

Answer 15

sudden eruption of multiple seborrheic keratosis caused by malignancy. MC is GI tract.

Question 16

What has a velvet like texture, benign 80% of the time in DM patients, malignant in 20% of the time with gastric implications?

Answer 16

Acanthosis nigricans

Question 17

Where is acanthosis nigricans located?

Answer 17

flexural areas (neck, axilla).

Question 18

What is a feature of Gardner’s syndrome?

Answer 18

Multiple epidermal inclusion cysts. AD disorder.

Question 19

What has a crateriform tumor, central keratin plug, rapid growth then spontaneous regression?

Answer 19

Keratoacanthoma

Question 20

the rapid appearance of large numbers of seborrheic karatoses is due to what?

Answer 20

elaboration of tgf-a.

Question 21

What is hyperkeratotic, pearly gray white plaques of scaly papules, and is a precursor of SCC?

Answer 21

Actinic keratosis

Question 22

What is the 2nd MCC of skin cancer?

Answer 22

squamous cell carcinoma

Question 23

where do you typically see actinic keratoses?

Answer 23

temple and forehead, and the back of a hand.

Question 24

What mutation is seen in SCC?

Answer 24

p53 mutations.

Question 25

What is the most common cause of cutaneous squamous cell carcinoma?

Answer 25

DNA damage induced by UV light because p53 function is lost.

Question 26

Does SCC have a good chance for mets?

Answer 26

no

Question 27

what causes basal cell carcinoma?

Answer 27

chronic exposure to UV light, occurs in sun-exposed areas, inner canthus of eye, upper lip

Question 28

what is the histology of basal cell carcinoma?

Answer 28

palisading nuclei

Question 29

What is AD, absence of function of PTCH gene causing uninhibited activation of SMO leading to dev of what?

Answer 29

nevoid basal cell

Question 30

what chr is PTCH located on?

Answer 30

9

Question 31

Which tumor is benign, slow growing, proliferation of scar-like tissue, and may have a hx of trauma?

Answer 31

benign fibrous histiocytoma

Question 32

what is xanthoma?

Answer 32

firm, raised, waxy papules. Associated w/ ab lipids in the blood.

Question 33

what is the progression of mycosis fungoides?

Answer 33

patch, plaque, nodule

Question 34

what is the histiological hallmark of mycosis?

Answer 34

sezart-lutzner cells - t helper cells (CD4 pos) that form bandlike aggregates w/i superficial dermis.

Question 35

darier sign, point mutation of c-KIT, release of histamine/heparin. brought upon by alcohol, opiates, salicylate

Answer 35

mastocytosis - urticara pigmentosis