BCC & SCC Flashcards
What are skin derivatives of ectoderm
- pilosebaceous units
- apocrine
- eccrine
- nail unit
- epidermis
What are skin derivatives of neuroectoderm
- melanocytes
- nerves
- specialized sensory receptors
What are skin derivatives of mesoderm
- adipocytes
- fibroblasts
- langerhans
- macrophage
- mast cells
- merkel cells
- blood vessels
- lymph vessels
what is epidermis
stratified squamous epithelium
What cell types are in the epidermis
- keratinocytes ++++
- melanocytes +++
- Langerhans ++
- Merkel +
What is the fitzpatricks classification
To describe Sun-Reactive Skin types
- I - White - always burn, never tan
- 2- White - usually burn, tan with difficulty
- 3- White - Sometimes mild burn, tan average
- 4- Moderate brown - Rarely burn, tan with ease
- 5- Dark Brown* - Very rarely burn, tan very easily
- 6 - Black - Donot burn, tan very easily
* asian, hispanic oriental, light african descent
What UV exposure is damaging to skin and what is the pathophysiology
UVB 290-320nm is carcinogenic
UVA 320-400nm - is mildly carcinogenic, synergistic w UVB
sunlight is 5% UVB, 95% UVA
photochemical effect - electron excitability in absorbing atoms induces damaging induces chemical changes
How are melaosomes protective against UV exposure
Melanin protect against UVB damage by reducing the amount of UVB delivered to the dermis
What are etiologies for cutaneous malignancies
- UV exposure
- immunosuppresion
- chemical carcinogenesis
- ionizing radiation
- inherited conditions
How do you prevent skin cancer exposure
- sunscreen - chemical - contianing PABA, and physical - zinc oxide/clothing
- education
What are etiologies of BCC development
- UV exposure
- Chemical exposure - arsenic
- Ionizing radiation exposure (latency 10-20yrs)
- Inherited conditions (Bazex, XP, Gorlin, Gardner, Albinism, Muir Torres)
- Immunosuppresion (loss of NK cells, T cells)
What is the distribution of BCC
Mainly on H&N, where most pilosebaceous units are located
Nose> Cheek >periorbital
How do you classify BCCs
N - Nodular ulcerative
O - Other (Micronodular, Infiltrative, Cystic)
P - Pigmented (most common in africain and hispanic
M - Morpheaform (perineural invasion, high recurrance rates)
S - Superficial (on the shoulder, red macular patch)
What are mimickers of BCC
- Merkel cell
- aggressive, metastasize to LN, bone, viscera
- Tx: WLE, SLNBx, radiation
- Adnexal Carcinoma
- uncommon, appear in elderly, high incidence of local recurrence
What is the histopathologic feature of BCC
- basoloid cell collections with peripheral palisading and stromal reaction (fibroblast and T cell infiltrates)
What is the rate of BCC metastasis?
0.04%
More aggressive BCC - morpheaform, infiltrative, micronodular
What is the natural history of BCC growth
growth at 0.5cm/yr
direct invasion into adjacent structures, may grow along perineural/lymphovascular structures
Slow growing
What are features of a BCC which make it high risk??
?????????need answers
- Location
- H-zone
What is Gorlin’s syndrome
Basal Cell Nevus Syndrome
- AD, PTCH gene mutation
Clinical features
- frontal bossing, pseudohypertelorism
- odontogenic mandibular keratocysts
- spina bifida, bifid ribs
- palmar and plantar pits, syndactyly
- falx cerebri, mental retardation
- medulloblastoma, meningioma, fetal rhabdomyoma, ameoloblastoma
Degeneraiton occurs post puberty
Tx - close observation and aggressive tx
possibel VIsmodegib systemic therapy - Shh inhibitor
WHat is XP
- AR, genetic mutation in endonuclease, required for repair of DNA damage post- UV exposure
Clinical features
- risk for BCC, SCC, melanoma
- Skin: early lentigos
- Ocular: corneal opacity, blindness
- Neurologic - deficits???
What is Bazex
- X-linked
Clinical features
- icepicks on hands - follicular atrophoderma
- hypotrichosis, anhydrosis
- BCC noted on face in teenage years
Management options for BCC
Medical
- Cryotherapy
- cure rate 90%
- BUT no tissue path, pigment loss in scar
- Radiotherapy
- single dose of 5-20Gy or multi sessions totaling to 35Gy
- cure rate 90%
- for elderly, large areas where surgical recon difficult/disfiguring
- BUT higher recurrence, poor cosmetic outcome
- Photodynamic Therapy
- Less effective than surgery!!! anything else?????/
- Chemotherapy
- Imiquimod (Aldara) for superficial BCC and AK
- TID for 6wks
- Cure 75-80%. imiquimod > 5-FU >PDT
- CO2 laser
- for superficial BCC, especially with coagulation disorders
Surgical
- Curettage & Dessication
- <1cm nodular exophytic lesions
- Cure rate 80-95% if <2cm
- But - get scar, little tissue to examine for path
- Dermabrasion and chemical peel
- premalignant lesions only
- Surgical Excision with Margins
- margins recommended are 2-5mm - dpeends on type, location, age, medical state
- 4mm margin to eradicate 95% tumors greater than 2cm
- Mohs fresh frozen techniue
- mass debulk w curette, thin area removed at 45’ w 2mm margin
- map of tumor is done with H slices and all margins are examined
- cure 99% 1’ BCC, 94-96% 2’ BCC
What is the risk of recurrence with a possitve margin
- 30% if deep margin +
- 15% if peripheral margin +
What are signs of BCC recurrence?
- development of papule/nodule within scar
- telangiectasia with enlarging scar
- scar erythema, crusting
- non-healnig wound
What are risk factors for BCC recurrence?
- young female
- located in midface/ear
- hx of radiation exposure
- BCC morpheaform or perineural invasion
- incompletely treated/recurrent disease
- large tumor >2cm
Wht is follow-up after diagnosis of BCC
q6mths for 5yrs
Because 4/10 patient who develop 1’ BCC will develop a second in next 5yrs
What is SCC?
Malignancy that develop in the malphigian layer o fthe pidermis (s. germinativum, s. basale)
How fast do SCC’s grow
cellular doubling time 4days
What are etiologic factors leading to SCC
- Chronic sun exposure
- Precursor lesions
- AK, AK, L, E, EdQ, P, KA
- Precursor condicitions
- XP, Epidermodysplasia Verruciformis, albinism, muir torre, porokeratosis
- Ionizing radiation
- Previous chronic wounds/scar
- EB, burn scar, pressure sore, venous stasis/arterial insufficiency, chronic draining OM sinus tract.
- Average time from injury to SCC is 20yr
- chemical carcinogens
- arsenic, psoralen, , nitrogen mustard
- Immunosuppression
- NK cells, Tcells depleted
- 50% of trasnplant pts will dveelop SCC in first 10yrs
- Vial infection
- due to chronic HPV 16.18 infections
- most common penile shaft, external labia, periungal
What is the epidemiology of SCC?
2nd most common skin cancer
M:F, 1:1000, Hx of NMSC
How is SCC classified
- SCC in situ
- Invasive SCC
- Verrucous Carcinoma
- low grade SCC with locald estruciton but no mets, apepars like verruca vulgaris
What are clinical features that distinguish ISCC from SCC in situ?
Insitu SCC
- scaly dull red plaque, sharply defined
SCC
- Initially: can be smooth, verrucous, papillomatous +/- ulceration
- Then become nodular, infiltrative, inflamed
What are the histopathologic features of SCC
H - Hyperkeratosis (much of s. corneum)
A - Acanthosis (much s.spinosum)
D -Dyskeratosis (premature keratinization of cells prior ot reaching keratinizing layer
P - Parakeratosis (retention of nuclei in s. corneum)
What are the histopathology features of insitu vs iSCC
In Situ
- atypical keratinocytes in “windblown” appearnce throughout layers of epidermis
- atypia may occur in hair follicles even in dermis but DO NOT invade the dermis
Invasive SCC
- as above but extend into dermis
- see “keratin pearls”
- degree of cellular differentiation determine grade of SCC
How do you grade SCC
Broder’s Grading Classification
- Well differentiated =<25% undifferentiated
- Moderately <50% undiff
- Poor <75% undifferentiated
- Anaplastic/pleomorphic >75% undiff
Degree of atypia relates to risk of recurrence
List histologic variants of SCC
Acantholytic (adenoid ) SCC
Adenosquamous SCC
Spindle cell SCC
Clear cell SCC
Verrucous SCC
KA
What immunohistochemical stains/antibodies are used to stain SCC
Cytokeratin
Epithelial membrane antigen
Use to identify source of tumor when poorly differentiated
WHat is ther ate of metastasis of SCC
2-5%
to LNs within first few yrs of diagnosis
- SCC on upper half of face drain to parotid LN
- SCC on lips/perioral drain to submental/upper Ij LN
- Cure rate for met SCC is 50% w surgery/Rtx, multimodal Tx
- 5yr survival 35%
What factors of SCC are associated with more aggressive tumor
- Location (lip & ear high recurrence)
- Size (<1cm, 1% met rate,>2cm, 10% metastatic rate)
- Histopathologic Grade (poorly diff 30% recur)
- Depth of invasion (ass. w recurrence, met, death, >6mm)
- Perineural invasion
- Lymphovascular invasion
- Recurrent SCC
- Immunosuppresion (frequent mets/recurrence)
- Marjolins ulcer (25% mets)
What is your DDX other than SCC for lesion that appears inflamed, ulcerated, nodule
- BCC
- AK
- KA
- Irrittaed SK
- Adnexal tumor
- Atypical fibroxanthoma
- merkel cell
- pyoderma granulosum
- pagets
What is the TNM stagin for SCC and BCC
Tumor
Tx, T0, Tis
T1 _<_2cm with <2high RFeatures
T2 >2cm or ANY tumor with >2Rfeatures
T3 Tumor w invasion to adjacent strucutres
T4 invasion to skeleton axial/sleketal/perineural to skull base
high risk Features:
- Depth : >2mm, clarke>IV, perineural inv.
- Anatomic location ; ear, hair bearing lip
- Differentiation; poorly/undiff
N
NxN0
N1 single ipsi LN >3cm
N2a single ipsi LN 3-6cm
N2b multiple LN <6cm
N2c bilat or contra lat LN <6cm
N3 any LN>6cm
M0
M1 distant mets
Staging
0 = Tis
1 = T1
2 = T2
3 = T3, N1 with T1-3
4= Any T4, N2/3, M1
What are the management options for SCC
Surgical Excision
- Margin 5-15mm
- SCC <2cm with 4mm margins, 95% will be cured.
- SCC <2cm with high risk features, do 6mm
- SCC 3cm, do 1.5 cm
- SLNBX indicated if clinically palpable nodes
EDC
- if <2cm and well defined border
RTx
- for eldely, medically unfirt, lips/ear/nose
- <2cm lesion, 85-95% cure rate
Medical tx
- Imiquimod for SCC in situ ONLY
What is f/u for SCC
q3mth for 3yrs then q6mth
