Skin Cancer Flashcards
Basal cell carcinoma is named for?
It appears blue (basophilic) like the basal layer because it is packed with proteins. Most likely arises from hair follicles and areas around them.
Squamous cell carcinoma resembles
spinous layer
Melanoma comes from
melanocytes
What is teh risk in the US of nonmelanoma skin cancer
1 in 5
Most common invasive neoplasm in US is
Basal Cell Carcinoma
What mutation is most common in BCC
PTCH (patch) present in 30% of sporadic tumors.
What the hell is the PTCH gene
its a tumor suppressor, regulates basal epidermal cell proliferation
Basal cell carcinoma histology
Basophilic, pleomorphic, hyperchromatic cells that form nodules which often extend from the epidermis
Look for the “palisade” at the periphery
Tumor nodules are set in a mucinous stroma
Basal cell nevus syndrome
Also called Gorlin syndrome. It is autosomal dominant and rare. A mutation of the PTCH1 tumor suppressor gene. You have your first basal cell carcinoma in your early 20s. Increased risk of other malignancues like medulloblastoma and fibrosarcoma. Jaw cysts and musculoskeletal disorder.
Be familiar with the sonic hedgehog pathway and the role that the pTCH gene plays in preventing SMO binding to SHH ligand.
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Metastasis in basal cell carcinoma is
RARE>
Treatment options for basal cell
excision is the main option electrodessication and curretage cryosurgery radiation topical treatment
What defines squamous cell carcinoma in situ
Full thickness epidermal atypia confined above the basement membrane.
Other names for SCC in situ: Bowen’s disease
Erythroplasia of Querat- on the glans penis
Minimal atypia (not full epidermal thickness) is called?
actinic keratosis
Three biggest risk factors for squamous cell carcinoma>
UV, HPV, Immunosuppression
Also: Inflammation Burn scars Chemical Exposure Radiation Exposure Leukoplakia
Risk of metastasis for cutaneous squamous cell carcinoma is based on
size of the tumor, depth of invasion into the dermis, anatomic site, host immune status
Larger than 2cm = greater risk
Greater than 4mm in depth= Greater risk
lips and ears= greater risk
What is the metastasis rate of SCC
less than 5%
What clinical scenarios often lead to higher rates of metastasis for SCC
Actinic induced on the lip
Marjolin’s ulcers
vulvar, perineal, pineal HPV induced
Leukoplakia- chewing tobacco
Highest risk for melanoma?
white men over 50
second most common age group for melanoma
25-29 yo
Most melanoma develops..
de novo
Melanoma has to be where in order to metastasize
has to be in the dermis
Three types of nevi (moles)
Junctional, Compound, Intradermal
Junctional nevi are what?
confined to the epidermis.
Remember than any nevi is a nest of melanocytes and 3 melanocytes make a nest.
Compound Nevi
Both in epidermis and dermis
Intradermal nevi
Nests in dermis only
What are some genetic predispositions to melanoma
CDNK2 and BRAF mutations
Melanoma risk factors?
Large number of common nevi Giant congenital nevi Atypical Nevi History of blistering sunburns Family History of melanoma Light complexion Underlying immune dysfunction
What is Acral Lentiginous melanoma
melanoma located on palmar and plantar surfaces.
Most common in pts with darker skin
Lentigo maligna>
Melanoma on the face. slow growing, usually shows up on old sun damaged skin
When lentigo maligna melanoma develops a nodule, thats a sign that….
it is invasive and not in situ
Nodular melanoma
usually appears on sun exposed skin.
No preceding radial growth
Superficial spreading melanoma
asymmetrical, irregular borders, wide variation in color, diameter over 6mm
red, white, and blue
melanomoa most commonly metastasizes to where>
skin…often via the lymphatics
Most common cause of death in melanoma
CNS involvement
Single most important prognostic factor for melanoma?
Lymph node involvement
What is the most important histologic prognostic factor for melanoma
Breslow thickness and ulceration
What is the breslow thickness
distance of involvement from the stratum granulosum to the deepest tumor cell
What drug is a small molecule molecular inhibitor of BRAF
Vemurafinib…
Approved for unresectable of metastatic melanoma
Provides modest survival benefit
Initially it works very well, but the melanoma adapts and can come up with alternative proliferation pathways
New trials are focused on combo therapy with ipilimumab
Xeroderma pigmentosum has what type of inheritance patter
Autosomal recessive
