Derm path II Flashcards
anucleate ghost cells
pilomatrixoma
hemangioma
red lump
xanthoma
yellow lump/bump
fibrohistiocytic lesion
tan
tan brown papule <1cm
sometimes tender
benign fibrous histiocytoma
dermatofibroma
same as benign fibrous histiocytoma
skin pigment where increased melanin in keratinocytes, no increase in # melanocytes
sun tan
freckles
cafe au lait spots
melasma
skin pigment wehre increased melanin in keratinocytes and small increase in # melanocytes
solat lentigo
loss of melanin in keratinoctes
vitiligo, acute transient
albinism
loss of melanocytes, permanent
vitiligo, chronic
what are types of acquired pigmentation
skin tattoo
amalgam tattoo
physiologic purpose suntan
increased protection against solar radiation (UV-B spectrum)
what is melasma
hypermelanosis
signs melasma
sharply demarcated blotchy brown macules on face
symmetrical distribution over cheeks and forehead
less frequently on upper lip and neck
what is chloasma
melasma on that face of someone who is pregnant
when does melasma occur
during pregnancy
in women taking oral contraceptive
at menopause
solar lentigo
benign discrete
hyperpigmented macule occurin in chronically sun exposed skin in adults (back of hand and forehead)
what causes solar lentigo
increased melanin pigment in keratinocytes
variable increase in number of junctional melanocytes
what does lentigo mean
proliferation of melanocytes
lentigo maligna
in situ melanoma in sun exposed skin of face
what is vitiligo
loss of melanin in keratinocytes
Tx for acute vitiligo
keratinolytic agents
removes layers of keratinocytes
what is albinism
defect in tyrosinase, enzyme necessary for melanin production
mutation in melanocytic nevi
acquired mutations in Ras signaling like NRAS and BRAF
what are junctional nevi
maculopapular visible appearance
small, flat and uniform
what are compound nevi
papular visible appearance
raised and dome shaped
nests and cords of dermal nevus cells
what are intradermal nevi
frequently nodular visible appearance
NO nests of melanocytes at dermal epidermal junction
large congenital nevus at risk for
melanoma risk
what do blue nevi look like
non nested ermal infiltration
assoc with fibrosis
highly dendritic and heavily pigmented
blue nevus can be confused with what
melanoma
what is a spitz nevus
spindle and epithelioid cell nevus
fascicular growth, large plump cells with pink-blue cytoplasms anf fusiform cells
spitz nevus confused with
hemangioma and melanomas
what is a halo nevus
lymphocytic infiltration surrounding nevus cells
what causes halo nevus
host immune response against nevus cells and surrounging normal melanocytes
nevus with cytologic atypida
dysplastic nevus
dysplastic nevus is a potential marker for
precursor melanoma
familial clark/dysplastic necus
autosomal dominant
CDKN2A and CDK4 mutations
appearance of dysplastic nevus
assymmetric
border irregular
color uneven
diameter >6mm
histo of dysplastic nevus
melanocytes as nests at tips of rete ridges
rete ridges are bridged
papillary dermis has increased fibrosis “fibroplasia”
subtypes of malignant melanoma
lentigo maligna
superficial spreading
nodular
acral lentiginous
what is lentigo maligna
in situ sun exposed area
superificial spreading malignant melanoma
in situ or invasive with mostly horizontal growth phase
nodular malignant melanoma
invasive mostly vertical growth phase
acral lentiginous
palms soles and subungual, non-caucasian, insitu or invasive
how do majority malignant melanomas originate
de novo, as isolated lesion
not usually next to melanocytic nevus
where does malignant melanoma mets to
lymph nodes, liver, lungs, brain
risk factors malignant melanoma
caucasians with fair skin
male gender
3 episodes of severe sunburn before age 20
prolonged MCB UV exposure with repeated sunburn
types of conditions of fair skin that increase risk of malignant malanoma 50-100 x
albinism or Xeroderma pigmentosa
mutation in majoirty of skin melanomas
increased telomerase activity from mutated TERT gene
Kit mutations
non sun exposed melanomas
mutations in dysplastic nevus and melanoma familial syndromes
CDKN2A mutations that inhibit P16 inhibition
CDK4 mutations block P16 inhbition
