Hi - Skin

Question 1

what stain is used in skin histopath

Answer 1

haemotoxin

Question 2

what colour do the epidermis and dermis stain

Answer 2

epi = purple
dermis = pink

Question 3

name a key component of the epidermis

Answer 3

keratinoytes

Question 4

name a key component of the dermis

Answer 4

collagen

Question 5

how long does it take cells to mature from the base to the surface of the epidermis

Answer 5

28 to 40 days

Question 6

name the layers of epidermis from outer to inner

Answer 6

desquamated cells
stratum corenum
stratum granulosum
stratum spinosum
BM

Question 7

what cell is present in the stratum spinosum

Answer 7

desmosomes

Question 8

in what layer do cells lose their nuclei & what is the benefit

Answer 8

straum corneum
- water tight layer

Question 9

where are melanocytes in epidermis

Answer 9

stratum spinosum

Question 10

what is present in the dermis

Answer 10

hair follicles
sweat glands

Question 11

name the 6 key types of inflammatory skin reactions

Answer 11

spongiotic
lichenoid
psoriasiform
vesiculobullous
graanulomatous
vasculitis

Question 12

give an example condition of spongiotic reaction

Answer 12

eczema

Question 13

what is the hallmark feature of spongiotic reaction

Answer 13

intraepidermal intercellular oedema

Question 14

what is the hallmark feature of lichenoid reaction

Answer 14

band of lymphocytes at epidermal/dermal junction causing keratinocyte death –> interface dermatitis
basal cell damage

Question 15

what is the hallmark feature of psoriasiform reaction

Answer 15

regular epidermal cells but hyperplasia –> thickened due to increased turnover of keratinocytes

Question 16

what is the hallmark feature of vesiculobullous reaction

Answer 16

blistering in and beneath epidermis

Question 17

why do you get oedema in spongiotic

Answer 17

lymphocyte infiltration brings in fluid in perivascular soace

Question 18

what does spongiotic look like

Answer 18

red, weepy rash with vesicles

Question 19

give an example condition for lichenoid

Answer 19

lichen planus

Question 20

describe lichenoid rash

Answer 20

shiny, purple, flat topped, scaly plaques and papules

Question 21

what line is characteristic of lichenoid

Answer 21

wickham striae - white lines

Question 22

describe histology of lichenoid

Answer 22

epidermal keratinocytes lose nuclei and apoptose
thickened epidermis
liquefaction degeneration of basal epidermis
melanin beneath epidermis
band of lymphocytes at epidermal/dermal junction causing keratinocyte death

Question 23

name a subset of lichenoid

Answer 23

erythema multiforme

Question 24

describe erythema multiforme rash

Answer 24

target lesion

Question 25

what is erythema multiforme similar to

Answer 25

TEN Sjorgrens

Question 26

give an example condition of psoriasiform

Answer 26

psoriasis

Question 27

describe psoriasiform rash inc location

Answer 27

erythematous plaques, with silver white scales on extensor surfaces - backs of elbows/knees

Question 28

describe Ix for psoriasiform rash

Answer 28

clinically usually biopsy

Question 29

what causes scales in psoriasiform rash

Answer 29

nuclei still present in keratinocytes in stratum corneum + neutrophils

Question 30

name 2 types of vesiculobullous

Answer 30

pemphigoid pemphigus

Question 31

describe rash of vesiculobullous

Answer 31

large tense bullae, intrinsicly pruritic

Question 32

pathophysiology of bullous pemphigoid

Answer 32

epidermal BM attacked by IgG AB eosinophils fluid filled space between epi/dermis = bullae

Question 33

where are bullae in pemphigoid

Answer 33

below epidermis

Question 34

Ix for pemphigoid and finding

Answer 34

direct immunoflurescence --> IgG attacking BM - linear IgG deposit at BM

Question 35

name 2 types of pemphigus and their distinction

Answer 35

folliaeceous - superficial vulgaris - deep

Question 36

pathophysiology of pemphigus

Answer 36

epidermal cells fall apart as intercellular junction (desmoglien 3) is attacked

Question 37

rash of pemphigus

Answer 37

blisters / crusts all over skin and mucous membranes

Question 38

Ix of pempigus and finding

Answer 38

immunoflurescence --> CHICKEN WIRE pattern of intercellular IgG deposits

Question 39

should pemphigus be Tx?

Answer 39

YES - fatal without tx

Question 40

what colour is skin tumour in PM

Answer 40

grey

Question 41

what RF are skin tumours related to & how

Answer 41

sun exposure - superifical solar ilastiosis (reduced collagen / elastic)

Question 42

name 2 benign skin cancers

Answer 42

seborrhoeic keratosis sebaceous cyst

Question 43

3 types of malignant skin cancer

Answer 43

basal cell carcinoma squamous cell carcinoma melanoma

Question 44

clinical features of basal CC

Answer 44

pearly, telangiectasia, rolled edges

Question 45

prognosis of basal CC inc mets / recurrence

Answer 45

virtually never mets but locally aggressive can recur

Question 46

what mutation is associated with basal CC

Answer 46

PTCH mutation for a TS gene

Question 47

histology of basal CC

Answer 47

blue tumour due to stain cleft artefact peripheral palisading - stand in line in nests

Question 48

histology of SCC

Answer 48

keratin pearls - form pink tumours due to keratin breaks through BM increased mitoses

Question 49

prognosis of SCC inc mets / recurrence

Answer 49

invasive - mets to distal sites by BVs more aggressive than BCC

Question 50

what preceeds SCC

Answer 50

acitinic keratosis

Question 51

describe histopath features of acitinic keratosis

Answer 51

rapid prolfieration atypia of epidermis

Question 52

how does acitinic keratosis invasiveness compare to SCC

Answer 52

AK = dysplasia - not broken through BM SCC = breaks BM

Question 53

clinical features of acitinic keratosis

Answer 53

rough, scaly

Question 54

what is bowens disease

Answer 54

full thickness atypia with BM intact

Question 55

3 types of benign naevi with location

Answer 55

junctional - epidermis compound - dermis / epidermis intradermal - dermis

Question 56

what causes benign naevi and how is it different to cancer

Answer 56

nesting of melanocytes --> its organised

Question 57

histology of benign naevi

Answer 57

nice, small nests well spaced smaller in depths of dermis

Question 58

clinical features of melanoma

Answer 58

ABCDE asymmetry border - irregular colour - irregular colouring / pink/red diameter - >6mm evolving - changing in size/shape/colour

Question 59

histology of melanoma

Answer 59

cellular atypia large melanocytes asymmetry pagetoid spread

Question 60

what is pagetoid spread of melanoma

Answer 60

melanocytes high in epidermis

Question 61

melanoma stains

Answer 61

melan A stain, S100, HMB45

Question 62

2 key prognostic indicators of melanoma

Answer 62

breslow thickness ulceration

Question 63

other prognostic indicators of melanoma

Answer 63

lymphovascular invasion perineural invasion clark level microsatellites TILs regression mitotic levels

Question 64

what is breslow thickness

Answer 64

granular layer to deepest keratinocytes

Question 65

name a common mutation seen in melanoma

Answer 65

BRAF V600E 20-30% of melanoma has this