Histopathology 11 - Dermatopathology Flashcards
Give an example of vesiculobullous inflammation?
Bullous pemphigoid
What are the aetiological agents of pemphigoid
IgG and C3
They attack the basement membrane and destroy the adhesion molecules
How can you confirm the diagnosis of pemphigoid?
Immunofluorescence of fresh samples to show IgG and C3
NB IgG binds to hemidesmosomes on the basement membrane
What causes pemphigus vulgaris?
Pemphigus antibody attacks proteins that holds cells together in the stratum spinosum, causing “akantholysis”, which leads to formation of *suprabasilar bulla*
On which surfaces does psoriasis tend to present?
Extensor (knuckles, knees)
Get silvery plaques
On which surfaces does eczema tend to present?
Flexor
What is the appearance of basal cell carcinomas?
Pearly white border
Central area of ulceration with telangiectasia
What do pre-cancerous skin cells (Bowen’s disease) look like histologically?
Pleomorphic
Atypical mitotic figures
All within the epidermis
What is the upward spread of melanocytes known as?
Pagetoid spread
When would mitotic figues in the skin not be alarming?
Pregnancy
The Breslow thickness is used to stage which skin cancer?
Malignant melanoma
Which common skin cancer does not metastasise?
Basal cell carcinoma
Is diameter or thickness more important for malignant melanoma?
Thickness
Which patient group is most at risk of pemphigus foliaceus?
The elderly - but it’s rare
Which cells of the immune system are most involved in eczema? (2)
T-cell mediated pathology
Eosinophils recruited to sites of inflammation
Where does fluid build in eczema, and what is this called?
Between keratinocytes
Called spongiosis
Which skin pathology appears as “silvery plaques”?
Psoriasis
Which immune-mediated skin condition causes a rapid turnover of keratinocytes?
Psoriasis
Which skin condition appears as white lines in the mouth + itchy purply red patches and plaques on the distal extensor surfaces?
Lichen planus
Called Wickham’s striae
Which skin condition appears as a “pigmented cauliflower” + has stuck-on appearance?
Seborrhoeic keratosis
Which skin condition forms “keratin horns”?
NB this is entrapped keratin surrounded by a proliferating epidermis
Seborrhoeic keratosis - get orderly proliferation of epidermis
Describe the appearance of a sebaceous cyst?
Round, smooth surface, non-mobile, central punctum
Which types of invasion is basal cell carcinoma most likely to exhibit?
Perineural or vascular
What is Bowen’s disease?
Pre-cancerous squamous cell carcinoma (SCC in situ)
Precedes basal cell carcinoma
Which type of skin cancer is most likely to become invasive and metastasise?
Squamous cell carcinoma
What is the fancy name for a mole?
Benign junctional naevus
Which type of skin cancer demonstrates upward migration of melanocytes?
Malignant melanoma
A lump on the upper lip may be due to which type of cancer?
Metastatic renal cell carcinoma
Where on the body does bullous pemphigoid present?
Get tense bullae on flexural surfaces
Presentation of pemphigus vulgaris
Flaccid-looking blisters, these rupture easily leaving a raw, red surface underneath
Aetiology of pemphigus foliaceus
- 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)
Shed time in psoriasis
Sheds RAPIDLY - every 7 days
NB normally should take 56 days
This rapid turnover is why epidermis gets a lot thicker
Pyoderma gangrenosum aetiology
- This is a form of vasculitis
- This is NOT actually gangrenous
- It presents as an ulcer
Lichen planus is an example of what type of inflammatory reaction pattern?
Lichenoid
Rodunt ulcer - has pearly edges + central ulcer + small capillaries seen + in sun-exposed area in elderly
Basal cell carcinoma
Does basal cellc carcinoma metastasise?
Nah - only locally invasive
What type of cell change do you get in Bowen’s disease?
full thickness dysplasia (so all the way through the epidermis)
NB this is pre-cancerous squamous cell carcinoma
Skin lesion with iregular outline + different colours + bleeding + itchy
Malignant melanoma
A to E for skin lesions
asymmetry
border irregularity
colours
diameter
evolution
How do normal melanocytes spread?
How does malignant melanoma spread?
Move down into the dermis?
get BIGGER and move up through the epidermis – this is known as Pagetoid spread
How to stage malignant melanoma
Look at depth (in mm)
Where in the epidermis does the bullae in pemphigus vulgaris form?
Between the keratinocytes: INTRA-EPIDERMAL
