Cancer Flashcards
What are the skin cancer progenitors for BCC?
Germinative keratinoctyes (resemble basal layer)
What are the skin progenitors for SCC?
Epidermal keratinocytes (resembles spinous layer)
What are the cancer progenitors for melanoma?
Melanocytes
What are the nonmelanoma skin cancer?
BCC and SCC
What’s the most common invasive neoplasm in the US?
BCC
What mutation is frequently found in sporadic cases of BCC?
PTCH
What’s the significance of the PTCH mutation in BCC?
Tumor suppressor gene: regulator of basal epidermal cell proliferation
What are the risks for BCC?
UV exposure, fair complexion, h/o sunburns (especially blistering), family history of BCC, Immunosuppression
[incidence increased by immunosuppression (10x), but not to same degree as SCC]
What is this?
BCC: nodular type
What’s this?
BCC
What’s this?
BCC: a nodule of basophilic, pleomorphic cells with hyperchromatic nuclei. Note the peripheral palisade of tumor cells and clefting from adjacent stroma
Describe the pathology of BCC
- Basophilic hyperchromatic cells that form nodules, often extending from the surface epidermis
- Cells at the periphery of the aggregations form a palisade
- Tumor nodules are set in a mucinous stroma, with retraction from that stroma (clefting, or ‘retraction artifact’)
Classic BCC (nodular): well circumscribed nodule with pearly rolled border and central erosion. Note telangiectasias as well.
BCC: telangiectasias (superficial dilated vessels) are prominent here
Superficial BCC
Pigmented BCC
Morpheaform BCC
Does BCC often present before age 50?
Nope. Only 20% of BCC presents before age 50 and it is rare prior to age 35.
What’s the genetic mutation that predisposes someone to getting BCC early?
PTCH tumor suppressor gene
What is basal cell nevus syndrome?
Autosomal dominant and rare mutation of PTCH1. Pts get BCCs at early age (~23yo). They also have MSK defects and jaw cysts
If someone has Basal Cell Nevus Syndrome are they at a higher risk of developing other neoplasms?
Yes. Increased risk of other neoplasms like medulloblastoma and fibrosarcoma
Is BCC likely to metastasize?
Nope it’s super rare
What arer the Tx for BCC mets?
Tx= Excision, Electrodessication and curretage, cryosurgery, radiation, and topical treatment for superficial BCC( Imiquimod, 5-flurouraci)
Is there targeted therapy for BCC?
Yep: Vismodegib
How does Vismodegib work?
Small molecule inhibitor: competitive antagonist of SMO
When is Vismodegib approved?
Approved for ‘advanced’ BCC:
Metastatic disease, Recurrent disease (post surgery), and Non-surgical candidates
What is the second most common skin CA?
SCC
What is the progression of SCC?
Actinic keratosis then SCC in situ followed by invasive SCC
What is actiinic keratosis?
Minimal atypia
What is SCC In SItu?
Full thickness epidermal atypia confined above the
basement membrane.
Bowens disease, Erythroplasia of Queyrat
What is the differentiation of invasive SCC?
Can be well, moderately or poorly differentiated.
Actinic Keratosis
Actinic Keratosis
How would one describe Actinic Keratosis?
As thin non ndurated lesions- Lack of induration is clue to superficial nature of lesions