Skin Pathology III Flashcards
melanocytic nests at rete ridges bridged at base
with increased fibrosis in papillary dermis
in dysplastic nevus
CDKN2A and CDK4
mutations in dysplastic nevus syndrome
auto dom
appearance of dysplastic nevus
asymmetric
border irregular
color uneven
diameter >6mm
all non-reassuring signs
advanced melanoma
vertical growth spread - spread into dermis and vessels
subtypes of malignant melanoma
1 - lentigo maligna
2 - superficial spreading - horizontal growth
3 - nodular - vertical growth
4 - acral lentiginous
acral lentiginous
subtype of malignant melanoma
-worse prognosis
on palms and soles
non-caucasian
site of malignant melanoma
mucous membrane, eye, genital, anus, oral cavity, etc.
malignant melanoma
primarily in adults
originates as isolated lesion
aggressive - significant mortality
risk fx for malignant melanoma
caucasian with fair skin
male
3 episodes of peeling or severe sunburn before age 20
prolonged UVB exposure
10-15% familial
TERT mutation
increased telomerase activity
present in 70% of skin melanomas
CDKN2A and CDK4 mutations
seen in dysplastic nevus and melanoma familial syndromes
involved in P16 inhibition
melanoma male vs female
female - leg
male - trunk
ABCD for melanoma
asymmetry
border
color
diamter - >6mm
melanocytic marker
HMB-45
distant mets
stage 4
mets to lymph nodes
stage II/III
breslow level
thickness of melanoma
from epidermal granular layer to deepest penetration of tumor
gives mortality
<1mm thick 92% 10 year
1-2mm thick 80% 10 year
loss of texture, leathery skin and wrinkling
solar elastosis
sailor and farmer skin
neoplastic proliferation of keratinocytes not yet involving full epidermal thickness
scaling and redness
actinic keratosis
solar keratosis
actinic keratosis
is pre-cancerous lesion
sun exposed areas
lips
actinic chelitis
erythematous red brown macule
or minimally elevated papule with overlying scales
actinic keratosis
cutaneous horn
excessive scale formation
in solar keratosis
progression to full thickness atypia - SCC in situ
squamous cell carcinoma
malignant proliferation of epidermal keratinocyte with potential for mets
long term sun exposure - UVB
bowen disease
SCC in situ
never kills patient - no mets
other causes of SCC
HPV
chronic ulcers
burns and radiation
chemical exposure - tar in chimney sweep scrotum, arsenic, tobacco, betel nut
predisposition to HPV
epidermodyspalsia verruciformis
nucleotide excision repair defect
xeroderma pigmentosa
second most common cutaneous malignancy
SCC
organ transplant pt on immunosuppressive therapy
prone to SCC
characteristics of SCC
in areas of greatest cumulative sun exposure
early invasion - small firm erythematous nodule
surface granular and bleed
older SCC - large, invasive, ulcerated
mortality quite low
rapidly growing neoplasm
keratoacanthoma
often involutes and clears spontaneously within 3 to 4 months
histo is SCC - now termed “SCC, keratoacanthoma type”
basal cell carcinoma
skin neoplasms originating from basal regenerative epithelium of epidermis
virtually never metastasizes**
nodular and sclerosing BCC
potential for local invasion and destruction of adjacent dermis
preference for hair bearing skin with extensive sun exposure
gorlin syndrome
nevoid basal cell carcinoma syndrome
auto dominant
multiple BCC before age 20
pits of palms and soles
gorlin associations
medulloblastoma - brain
ovarian fibroma
odontogenic keratocytes
mutations of gorlin
SHH
PTCH
SMO
normally - SHH binds PTCH and SMO complex - activating GLI1
mutation in PTCH, less often SMO - allow constitutive activation of GLI1
most common cutaneous neoplasm
BCC
98% develop after age 40
same male and females
rodent ulcer
advanced BCC
nodular BCC
traditional or classic appearance
dome shaped - pearly papule or nodule
surface telangiectasias
may become quite large if neglected
pearly telangiectasia nodule
nodular BCC
histo - composed of nests of uniformly atypical basaloid cells within dermis
separated by stroma by clefts**
clefts
in nodular BCC
sclerosing BCC
morpheaform
- predominantly on face
- rodent ulcer**
difficult to excise, high recurrence, disfiguring
superficial BCC
scaly plaque - eleated rolled edges
-non-sun exposed skin
easily excised
-do recur
bednar tumor
pigmented dermatofibrosarcoma protuberans
dermatofibrosarcoma protuberans
superficial fibroblastic neoplasm
-fibrosarcoma of skin
local aggressive - rare mets
mutation in dermatofibrosarcoma protuberans
translocation of COL1A1 and PDGFB
-increased PDGFB
storiform swirling of spindle cells
dermatofibrosarcoma protuberans
also see swiss cheese infiltrates
cutaneous T cell lymphoma
infiltrate of atypical lymphocytes accumulate under epidermis
firm nodule arising in ulcerated aggregates in indurated plaque on trunk
dermatofibrosarcoma protuberans
mycosis fungoides
cutaneous T cell lymphoma
-CD4
chronic process
aggressive - survival 8-9 years
more in males
sezary syndrome
seeding of blood by malignant T cells with diffuse erythema and scaling - erythroderma**
CD4 T cells
cerebriform nucleus
of CD4 T helper cells
-in sezary syndrome
with mycosis fungoides
