Pathology Flashcards
the dermis contains a matrix of collagen and elastic fibres. when is it lost
smoking
sun damage
age
what is acanthosis
increased epidermal thickness
what is parakeratosis
nuclei in keratin layer
what is hyperkeratosis
increased thickness of keratin layer
what is spongiosis
oedema between squamous cells causing increased prominence of intercellular prickles
what is the pathogenesis of psoriasis
unknown
may be hereditary
may be due to epidermal hyperplasia
may be complement mediated attack on keratin layer
what is a key diagnostic feature of psoriasis histologically
munro micro abscesses
describe the psoriasis rash
silvery scale with raised plaque
well defined
bilateral/symmetrical on extensor
may be on chest/abdo
true/false - psoriasis has nail changes
true - it can
describe histology of psoriasis
elongation of rete ridges, island sections of dermis behind
munro micro abscess
lymphocytes in dermis
describe the rash of lichen planus
itchy flat topped violaceous papules
might see striae in oral mucosa
describe histology of lichen planus
irregular sawtooth acanthosis
hypergranulosis and orthohyperkeratosis
upper dermal infiltrate of lymphocytes
basal damage
describe pathology of pemphigus vulgaris
IgG against desmoglien 3 which maintains esmosomes in prickle cell layer, immune complexes form causing acantholysis and weak blisters that rupture to form erosions
where would you see pemphigus vulgaris
oral mucosa and GI tract and respiratory
scalp, trunk, face, axillae groin
what would you see histologically in pemphigus vulgaris
blister epidermally due to prickle cell separation
describe formation of bullous pemphigoid
Auto-IgG against hemidesmosomes binding basal cell layer to BM, so whole epidermis blisters
what test may be useful in pemphigus vulgaris and bullous pemphigoid
immunofluorescence
describe where you might see acne
head, face, neck, shoulders, back and chest
describe the pathology of acne vulgaris
increased androgens at puberty and increased sensitivity to sebaceous glands
keratin plugs pilosebaceous unit abd infection with corynebacterium acnes, produces comodome
if ruptures then scars
what is rosaecea and who is it more common in
females
recurrent facial flushing, pustules, visible blood vessels, rhinophyma
causes of rosaecea
sunlight
alcohol
spicy foods
stress
describe pathology of rosacea
vascular ectasia patchy inflammation with plasma cells pustules perifollicular granulomas follicular demodex mites
how would seborroheic keratosis appear on histology
epidermal acanthosis
hyperkeratosis
horn cysts
what is the leser-trelat sign
eruptive seborrhoeic keratosis signifying internal malignancy
what is bowens disease
squamous cell carcinoma in situ
scaly plaque, irregular border
what is actinic keratosis
precursor of invasive SCC
where are viral lesions and what type of virus causes and consequences
anogenital skin, HPV type 16
very dysplastic and often found in penile cancer
3 types of BCC
nodular
superficial
infiltrative
how does BCC appear histologically
epidermis originating and invasive into dermis
peripheral palisading
does BCC metastasise
rarely
sites of SCC?
sun damaged skin, elderly
leg ulcer
burns sites
xeroderma pigmentosum
adverse prognostic features of SSC
> 4mm thick
lymphatic/vascular invasion
perineural spread
scalp, ear, nose involvement
