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