Chapter 11 - Skin Cancer Flashcards
Skin Cancer highest incidence transplant pop
SCC
RF non-melanoma skin cancer
Fair skin light eyes Blistering sunburns, sun exposure FHx Prior skin cancer Chemical exposure (arsenic) Genetic Syndrome Male, Old Immunosuppressed Ionizing radiation (BCC, SCC) Smoking, HPV (SCC)
Skin cancer incidence
Melanoma 5% of skin cancer but 90% of Mortality pts < 50
20% will develop skin cancer in lifetime
4 rare skin cancers
Merkel cell
Dermatofibrosarcoma Protuberans
Sebaceous carcinoma
Cutaneous T cell lymphoma
BCC: classic appearance, worst recurrence types
75% of non-Mel skin Ca
Skin-pink pearly papule/plaque, rolled border, poss central ulcer
Desmoplastic (look like scar) and basosquamous
Bowen’s disease
SCC In situ
Confined to epidermis
Thin pink scaly papule/plaque
Location of HPV SCC
Hands, feet, genitals
Classic SCC appearance
Pink crusted papule /nodule
Metastasis risk of SCC
Less than 5% unless high risk:
Ear/Lip/Genitalia
HPV, site of chronic inflammation, rad/chemical
Poorly Diff, >2cm, >4mm depth, recurrence, perineural invasion
Immunosuppressed, xerod pigment
Risk of SCC In transplant
100x more likely
10x more likely to get BCC
0-17x more likely melanoma
Merkel cell CA
Rapidly enlarge violaceous/pink nodule Polyomavirus 30% Mets @ Pres Excise, LN, Rads 30% 5-yr Mortality
Keratoacanthoma
Nodule enlarges over 2wk, treat as well-Diff SCC
Dome shaped, central crater
Actinic Keratosis
Pink scaly papule
1/10-1000 turn into SCC per year
Tx: liq nitrogen If multiple (field Tx): 5FU, imiquimod, 415nm blue light, peels
Actinic cheilitits
Lower lip, pre-SCC, more risk than keratosis
Blur verm border, papules/scale
Tx like keratosis
If SCC develops: vermillionectomy, advancement flap
Mohs cure rates
99% primary BCC/SCC
Less for high risk or recurrent
IHC stains for melanoma in situ and Pagets (extramammary), and SCC
MART-1, Mel-5
Cytokeratin 7
AE1-3
Locations treatable by Mohs
Hand, feet, genitalia
Face, neck, scalp
Other spots if recurrent, large, aggressive
Non-Mohs Tx for BCC/SCC
Excision (4-5mm margins)
Electrodessication (low risk)
If superficial: 5FU, imiquimod, photo
Rads: inoperable, adjuvant
Vismodegib
Inhibits pathway of PTCH gene mutations (majority of sporadic BCC, basal cell Nevus syndrome)
Prevents new BCC and kills existing ones
For advanced or metastatic
AE: non-scar alopecia, dysguesia, cramps, teratogenic
Melanoma: Biology, RF, 4 types
Melanocytes present in basal layer and nevi
Fair skin, intense intermittent UV exposure (most common Ca in F 25-29)
Only 25% arise from moles
Sup Spread (70%), Nodular (15-30%), Lentigo Maligna (15%), Acral Lentiginous (5-10%)
Typical melanoma diameter
> 6mm (pencil eraser)
Still Bx smaller suspicious lesions
Which moles to be sure to evaluate
Any new pigmented lesion in patient > 35 yo
Lentigo Maligna
Melanoma in Situ
Slow grow, irregular hyperpigmented patch, sun-exposed skin
Called melanoma if invade dermis. Elderly. Cumulative sun exposure
RF Melanoma
CDKN2A mutations
> 50 benign nevi
Large congenital nevi (>20cm)
Dysplastic Nevus Synd (atypical moles plus FH melanoma)
In-transit Met vs Satellite
1: >2cm from primary, not beyond regional LN
2: >2cm from primary
Melanoma T Stage
<1mm (90-97)
- 01-2mm (78-90)
- 01-4mm (65-78) (4: 45-65)
a without ulceration, mitosis <1/mm2
b with ulceration or mitosis > 1/mm2
For all stages besides 1, just ulceration
Mel N Stage
2 node a micro b macro
2-3 nodes c in-transit/sat no met
4+, matted, or intransit/satellite plus metastatic
Mel M Stage
1a skin/SQ/modal distant Mets
1b Lung
1c other visceral or any distant plus elevated LDH
Margins for melanoma excision
In situ: 0.5 cm
Depth 0-1mm: 1cm
Depth 1.01-2mm: 1-2cm
Depth >2mm: 2cm
Treatment Metastatic Melanoma
Traditional chemo rad not very effective
Target gene therapies:
Vemurafenib (BRAF)
Trametinib (MEK)
Ipilumab (CTLA-4)
Stage Group Melanoma and 5 yr survival
1A- T1A (97) 1B- T2a (93) 2A- T2b (82), 3a (79) 2B- 3b, 4a (68-71) 2C- 4b (53) 3 - Nodes, no Mets (40-78) 4- M1, (9-27)
UV Light
C- blocked by atm, B somewhat blocked. C shortest wavelength
95% what reaches us is A
DNA mutations, immunosuppression in skin (decreases DNA repair)
Tan Beds - UVA
Photo protection
Avoid sun 10am-2pm
Clothing, wise hat
Screen: absorb/scatter UV light, want broad spectrum, reapply a 2-4hr
SPF based on 2mg/cm2
T stage SCC
1: <2cm is 0-1 high risk features
2: >2cm or 2/3+ high risk features
3: maxilla, mandible, orbit, T Bone
4: invade skeleton or perineural skull base invasion
High risk: breakdown >2mm, ear/lip, poor diff
