Pathology Flashcards
name a benign epidermal tumor
seborrheic keratosis
who commonly gets seborrheic keratosis?
older individuals
what is seborrheic keratosis?
a benign proliferation of epidermal keratinocytes
where do seborrheic keratosis’ normally affect?
face
trunk
what is lesser trelat sign and what can it indicate?
eruptive appearance of many seborrheic keratosis lesions
may indicate internal malignancy
name two precursors for SCC
bowen’s disease
actinic keratosis
where is bowen’s disease commonly found?
the legs
what is bowen’s disease?
squamous cell carcinoma in situ
describe the appearance of bowen’s disease
scaly patch with an irregular border
where is actinic keratosis often found?
the head and neck
what is actinic keratosis?
variable epidermal dysplasia
what virus is SCC associated with?
HPV 16
what are the two non melanocytic skin malignancies?
basal cell carcinoma
squamous cell carcinoma
where is basal cell carcinoma found?
sun exposed sites
who is most commonly affected by BCC?
middle aged and elderly
what are the three main subtypes of BCC?
nodular
superficial
infiltrative
what is another name for infiltrative BCC?
morphoeic
where are melanocytes derived from?
the neural crest
what gene turns phaeomelai into eumelanin?
MC1R
what does one defective copy of MC1R cause?
freckles
what does two defective copies of MC1R cause?
red hair
freckles
what are ephilides?
freckles
patchy increase in melanin pigmentation
when do freckles develop?
after UV exposure
what is another name for actinic lentigines?
solar lentigines
age/liver spots
what are the four main types of melanoma?
superficial spreading
acral lentiginous
lentigo maligna
nodular
what is the most common type of melanoma?
superficial spreading
where is superficial spreading melanoma commonly found?
trunk
limbs
where are melanocytes found in the skin?
DEJ of the basal layer
what do melanocytes do?
synthesise melanin
transfer it to keratinocytes via dendritic processes
where are langerhans cells found?
the epidermis
what type of cells are langerhans cells?
dendritis
what dermis lies just beneath the epidermis?
papillary dermis
what are the two parts of the dermis?
papillary
reticular
what is hyperkeratosis?
increased thickness of the keratin layer
what is parakeratosis?
persistence of the nuclei in the keratin layer
what is acanthosis?
increased thickness of the epithelium
what is papillomatosis?
irregular epithelial thickening
what is spongiosis?
oedema between keratinocytes
what are the four main reaction patterns found in inflammatory skin diseases?
spongiotic
psoriasiform
lichenoid
vesiculobullous
what characterises psoriasis?
increased epidermal turnover
what is the koebner phenomenon?
new psoriasis lesions at sites of trauma
what are munro micro abscesses in psoriasis?
collections of neutrophils in the upper layers of the epidermis
what characterises lichenoid disorders?
damage to basal epidermis
what is the prototypic lichenoid disorders?
lichen planus
what is seen on histology of lichen planus?
irregular sawtooth acanthosis
name three immunobullous diseases
pemphigus vulgaris
bullous pemphigoid
dermatitis herpetiformis
what is the pathophysiology behind pemphigus vulgaris?
loss of integrity of epidermal cell adhesion
what medication does pemphigus vulgaris respond to?
steroids
what is dermatitis herpetiformis associated with?
coeliac disease
what is the hallmark of coeliac disease?
papillary dermal micro abscesses
