Histopathology 11 - Dermatopathology

Question 1

Give an example of vesiculobullous inflammation?

Answer 1

Bullous pemphigoid

Question 2

What are the aetiological agents of pemphigoid

Answer 2

IgG and C3

They attack the basement membrane and destroy the adhesion molecules

Question 3

How can you confirm the diagnosis of pemphigoid?

Answer 3

Immunofluorescence of fresh samples to show IgG and C3

NB IgG binds to hemidesmosomes on the basement membrane

Question 4

What causes pemphigus vulgaris?

Answer 4

Pemphigus antibody attacks proteins that holds cells together in the stratum spinosum, causing “akantholysis”, which leads to formation of *suprabasilar bulla*

Question 5

On which surfaces does psoriasis tend to present?

Answer 5

Extensor (knuckles, knees)

Get silvery plaques

Question 6

On which surfaces does eczema tend to present?

Answer 6

Flexor

Question 7

What is the appearance of basal cell carcinomas?

Answer 7

Pearly white border
Central area of ulceration with telangiectasia

Question 8

What do pre-cancerous skin cells (Bowen’s disease) look like histologically?

Answer 8

Pleomorphic
Atypical mitotic figures
All within the epidermis

Question 9

What is the upward spread of melanocytes known as?

Answer 9

Pagetoid spread

Question 10

When would mitotic figues in the skin not be alarming?

Answer 10

Pregnancy

Question 11

The Breslow thickness is used to stage which skin cancer?

Answer 11

Malignant melanoma

Question 12

Which common skin cancer does not metastasise?

Answer 12

Basal cell carcinoma

Question 13

Is diameter or thickness more important for malignant melanoma?

Answer 13

Thickness

Question 14

Which patient group is most at risk of pemphigus foliaceus?

Answer 14

The elderly - but it’s rare

Question 15

Which cells of the immune system are most involved in eczema? (2)

Answer 15

T-cell mediated pathology
Eosinophils recruited to sites of inflammation

Question 16

Where does fluid build in eczema, and what is this called?

Answer 16

Between keratinocytes

Called spongiosis

Question 17

Which skin pathology appears as “silvery plaques”?

Answer 17

Psoriasis

Question 18

Which immune-mediated skin condition causes a rapid turnover of keratinocytes?

Answer 18

Psoriasis

Question 19

Which skin condition appears as white lines in the mouth + itchy purply red patches and plaques on the distal extensor surfaces?

Answer 19

Lichen planus

Called Wickham’s striae

Question 20

Which skin condition appears as a “pigmented cauliflower” + has stuck-on appearance?

Answer 20

Seborrhoeic keratosis

Question 21

Which skin condition forms “keratin horns”?

NB this is entrapped keratin surrounded by a proliferating epidermis

Answer 21

Seborrhoeic keratosis - get orderly proliferation of epidermis

Question 22

Describe the appearance of a sebaceous cyst?

Answer 22

Round, smooth surface, non-mobile, central punctum

Question 23

Which types of invasion is basal cell carcinoma most likely to exhibit?

Answer 23

Perineural or vascular

Question 24

What is Bowen’s disease?

Answer 24

Pre-cancerous squamous cell carcinoma (SCC in situ)

Precedes basal cell carcinoma

Question 25

Which type of skin cancer is most likely to become invasive and metastasise?

Answer 25

Squamous cell carcinoma

Question 26

What is the fancy name for a mole?

Answer 26

Benign junctional naevus

Question 27

Which type of skin cancer demonstrates upward migration of melanocytes?

Answer 27

Malignant melanoma

Question 28

A lump on the upper lip may be due to which type of cancer?

Answer 28

Metastatic renal cell carcinoma

Question 29

Where on the body does bullous pemphigoid present?

Answer 29

Get tense bullae on flexural surfaces

Question 30

Presentation of pemphigus vulgaris

Answer 30

Flaccid-looking blisters, these rupture easily leaving a raw, red surface underneath

Question 31

Aetiology of pemphigus foliaceus

Answer 31

* You don’t see the intact bullae because these are so thin that they come off easily * Looks excoriated, the stratum corneum has lifted off (top layer lifts off)

Question 32

Shed time in psoriasis

Answer 32

Sheds RAPIDLY - every 7 days NB normally should take 56 days This rapid turnover is why epidermis gets a lot thicker

Question 33

Pyoderma gangrenosum aetiology

Answer 33

* This is a form of vasculitis * This is NOT actually gangrenous * It presents as an ulcer

Question 34

Lichen planus is an example of what type of inflammatory reaction pattern?

Answer 34

Lichenoid

Question 35

Rodunt ulcer - has pearly edges + central ulcer + small capillaries seen + in sun-exposed area in elderly

Answer 35

Basal cell carcinoma

Question 36

Does basal cellc carcinoma metastasise?

Answer 36

Nah - only locally invasive

Question 37

What type of cell change do you get in Bowen's disease?

Answer 37

full thickness dysplasia (so all the way through the epidermis) NB this is pre-cancerous squamous cell carcinoma

Question 38

Skin lesion with iregular outline + different colours + bleeding + itchy

Answer 38

Malignant melanoma

Question 39

A to E for skin lesions

Answer 39

asymmetry border irregularity colours diameter evolution

Question 40

How do normal melanocytes spread? How does malignant melanoma spread?

Answer 40

Move down into the dermis? get BIGGER and move up through the epidermis – this is known as Pagetoid spread

Question 41

How to stage malignant melanoma

Answer 41

Look at depth (in mm)

Question 42

Where in the epidermis does the bullae in pemphigus vulgaris form?

Answer 42

Between the keratinocytes: INTRA-EPIDERMAL