Benign epidermal tumors

Question 1

When do SK’s start?

Answer 1

4th decade of life usually

Question 2

Genetic mutations associated with seborrheic keratoses?

Answer 2

Activating mutations in FGFR3 and PIK3CA

Question 3

Where don’t SK’s form?

Answer 3

Mucous membranes, palms and soles

Question 4

Are HPV viruses located in SK?

Answer 4

SK’s in the genital region are likely condyloma acuminatum. Recommend bx. -HPV has been detected frequently in SK of the groin

Question 5

What conditions are associated w/ an abrupt appearance/increase in # of SK”s followed by regression when condition resolves

Answer 5

Pregnancy, co-existing inflammatory dermatoses (in particular erythroderma), and malignancy.

Question 6

What cancers are associated with leser-trelat

Answer 6

Adenocarcinoma of the breast, colon, gastric and lymphoma

Question 7

Where is leser-trelat usually seen?

Answer 7

On the back, can have itching, can have malignant acanthosis nigracans

Question 8

What is a lichenoid keratosis?

Answer 8

Inflammation/regression of benign lentigo, sk, or ak

Question 9

What do lichenoid keratoses look like clinically?

Answer 9

Pink papule, scaly, most common on the forearm and upper chest (mimics BCC or SCCIS)

Question 10

What is a path difference between deratosis papulosa nigra and SK?

Answer 10

DPN is like an SK w/o the pseudohorn cysts

Question 11

What virus is stucco keratosis associated with?

Answer 11

HPV-23b

Question 12

How can you get rid of stucco keratosis?

Answer 12

Suggest keratolytics

Question 13

Varients of porokeratosis?

Answer 13

• Porokeratosis of Mibelli
• Disseminated superficial actinic porokeratosis
• Linear porokeratosis
• Punctate porokeratosis
• Porokeratosis palmaris, plantaris, et disseminata
• Porokeratotic eccrine ostial and dermal duct nevus

Question 14

What are the risk factors for porokeratosis that increase the risk of complications, such as malignant transformation?

Answer 14

Length of time w/ lesion, older pts, linear variants

Question 15

Which type of porokeratosis has the lowest risk of malignant change

Answer 15

DSAP

Question 16

What is Flegel’s dz?

Answer 16

Hyperkeratosis lenticularis perstans

• Rare AD, mid to late adulthood -asymptomatic disc-shaped keratotic papules on distal extremities
• Electron microscopy: absent or altered Odland bodies (lamellar granules) which leads to hyperkeratosis

Question 17

Should you bx cutaneous horns?

Answer 17

Yes, in situ or invasive SCC present in up to 20% of lesions.

Question 18

Most common location of clear cell acanthoma?

Answer 18

Solitary papule or plaque on leg.

• Lesions are blanchabe, erythematous, and discrete; they may have attached wafer-like scale at the periphery
• String of pears of vessels in clear cell acanthoma

Question 19

What is the cause of the clear cells in clear cell acanthoma?

Answer 19

Increased glycogen in the cell accounts for their clear appearance and is due to a defect in phosphorylase

Question 20

What is a key feature of IFK compared to SK?

Answer 20

Squamous eddies. These are signs that skin has been irritated.

Question 21

What lesion looks like a single spot of darier?

Answer 21

Warty dyskeratoma

Question 22

Histology of warty dyskeratoma?

Answer 22

Invaginated cup with dyskeratosis and acantholysis

Question 23

What genes are associated with epidermal nevus?

Answer 23

FGFR3, PIK3CA, HRAS>NRAS>KRAS

Question 24

DDX for comedones on face?

Answer 24

Favre racouchot (old sun-damaged skin, lateral cheeks) , chloracne, nevus comedonicus

Question 25

What do you treat confluent and reticulated papillomatosis with?

Answer 25

Oral minocycline (50% success) then could do retinoids

Question 26

Distribution of SK's usually?

Answer 26

Sun-exposed areas, not as apparent on double-clothed areas (areas underwear covers)

Question 27

Clinical presentation of porokeratosis of Mibelli?

Answer 27

In kids infancy or childhood usually on distal extremity often several cm in diameter

Question 28

Clinical presentation of disseminated superficial actinic porokeratosis?

Answer 28

Onset in middle age, F\>M; numerous brownish-red macules w/ keratotic borders on sun-exposed areas (m/c is the legs, rare on the face) ## Footnote Immunosuppression is a risk factor

Question 29

Clinical presentation of linear porokeratosis?

Answer 29

Streaks along the lines of Blaschko: arise during infancy or childhood ## Footnote **Highest risk of progressing to SCC**

Question 30

Clinical presentation of punctate porokeratosis?

Answer 30

Onset in adolescence; 1-2mm "seed-like" papules on palms and soles

Question 31

When do epidermal nevi typically occur?

Answer 31

In the first year of life

Question 32

What is the presentation of porokeratosis palmaris, plantaris, et disseminata?

Answer 32

Onset is in childhood/adolescence - AD genodermatosis - Occurs on the palms/soles initially as uniform hyperkeratotic lesions that look like poro and then involve other areas that are non-sun exposed

Question 33

Clinical presentation of porokeratosis ptychotropica?

Answer 33

Red to brown papules and verrucous plaques in the intergluteal cleft on the buttocks

Question 34

What is the clinical description of epidermal nevi?

Answer 34

Papillomatous, pigmented, linear plaques along Blaschko's lines

Question 35

What are the 4 variants of epidermal nevus?

Answer 35

Nevus unius lateris: extensive b/l lesions on trunk Inflammatory linear verrucous epidermal nevus (ILVEN): Along lines of Blaschkow without neurologic defects Epidermal nevus syndrome: Schimmelpenning syndrome: a/w developmental abnormalitiees (neuro and MSK)

Question 36

What is the clinical presentation of nevus comedonicus?

Answer 36

A linear array of comedones on the face\>trunk (happens in childhood but worsens during puberty)

Question 37

What genetic abnormalities are involved in nevus comedonicus?

Answer 37

FGFR2 mutations: Alagille syndrome, apert syndrome, cardiocranila syndrome, and Crouzon syndrome