Non-melanomatous skin lesions

Question 1

what are seborrheic keratosis?

Answer 1

benign proliferation of epidermal keratinocytes
stuck on greasy hyperkeratotic surface
common on face and trunk in ageing skin

Question 2

what occurs with seborrheic keratosis?

Answer 2

epidermal acanthosis
hyperkeratosis
horn cysts

Question 3

what do seborrheic keratosis look like on histology?

Answer 3

massive thickening of prickle layer with groups of keratinocytes?
circles that look like onions

Question 4

what are the 3 subtypes of BCC?

Answer 4

nodular
superficial
infiltrative

Question 5

how do BCCs develop?

Answer 5

basal cells sprout from the epidermis and groups of cells invade into dermis
peripheral palisading

Question 6

do BCCs spread?

Answer 6

no

slow growing so can divide and grow but don’t metastasise

Question 7

which type of BCC is most dangerous?

Answer 7

infiltrative
may infiltrate tissues or spread along nerves
poorly defined

Question 8

physical appearance of BCC?

Answer 8

shiny/pearly

arborizing vessels

Question 9

what is palisading?

Answer 9

cells line up in a palisade (Picket fence) around the edge of the lesion
seen in nodular BCC

Question 10

what are superficial BCCs confused with?

Answer 10

eczema as they are almost flat and crusty and are poorly defined

Question 11

how do superficial BCCs grow?

Answer 11

spread along the base of epidermis and can have gaps so are poorly defined

Question 12

what does morphoeic look like?

Answer 12

lots of fibroblasts and collagen

looks like a scar

Question 13

where are BCCs usually derived from?

Answer 13

hair follicle

Question 14

what is bowens disease?

Answer 14

in situ SCC

usually in older females legs

Question 15

what does bowens disease look like?

Answer 15

scaly patch/plaque
irregular border
no dermal invasion
yellowish crust sometimes

Question 16

what happens in bowens?

Answer 16

some cells keratinise prematurely - dysplasia

Question 17

when does bowens disease become dangerous?

Answer 17

when the dysplasia crosses the basement membrane

Question 18

who/where is actinic keratoses (AK) usually seen?

Answer 18

on sun exposed (hands, scalp) skin in people with lots of outdoor sun exposure

Question 19

what are AK?

Answer 19

premalignant dysplasia of epidermis

SCC precursors

Question 20

what do AK look like?

Answer 20

small crusty lesions

Question 21

AK histology?

Answer 21

parakeratin - epidermis is turning over too quickly as turning malignant
nuclei retained in keratin layer
squamous dysplasia

Question 22

name some viral lesions that are precancerous?

Answer 22

erythroplasia of Queryat-penile bowens

associated with HPV

Question 23

which HPV is associated with dysplasia?

Answer 23

16

Question 24

common site of SCC?

Answer 24

sun exposed sites

Question 25

occasional SCC sites?

Answer 25

chronic ulcers burns sites chronic lupus

Question 26

rare site of SCC?

Answer 26

XP | EB

Question 27

how do SCC behave?

Answer 27

locally invasive metastases risk but not always scalp, ear, nose = more likely to spread can spread via lymphatic, vascular or perineural

Question 28

SCC histology?

Answer 28

groups of squamous/atypical cells invading the dermis

Question 29

peri/intra neural spread?

Answer 29

``` peri = spread around/with the nerves intra = invades the nerve and spreads with it ```

Question 30

peri/intra neural spread?

Answer 30

``` peri = spread around/with the nerves intra = invades the nerve and spreads with it ```

Question 31

what do merkel tumours look like?

Answer 31

sheets of dense neuroendocrine cells/tumour

Question 32

what is the leser trelat sign?

Answer 32

eruptive appearance of many seborrheic kertoses