14. Skin Cancer Flashcards
Outline the risk factors for melanoma
FH, many moles, atypical or dysplastic moles, poor immune system, excessive UV exposure, red/blond hair
Outline the pathophysiology of melanoma
Devel from epidermal melanocytes that have out-of-control growth
What are the signs and symptoms of melanoma?
Mole that is increasing in size, has irregular edges, change in colour, itchiness, skin breakdown
3 MAIN TYPES:
- Superficial: flat, irregular shape/colour, black/brown
- Nodular: raised, faster growing, some not coloured, black/blue/red
- Lentigo maligna: older skin, face/neck/arms
Nail: single pigmented band, nail lifting off
How should melanoma be investigated?
Skin exam, tissue biopsy, sentinel node biopsy
o A = asymmetry o B = border uneven, ragged, notched o C = colouring of diff shades of brown o D = diameter >6mm o E = evolves over time
REFER if = >3 points, suspected nodular MM, dermoscopy suggests melanoma
Major (2) = change in size, irregular shape, irregular colour
Minor (1) = >7mm, inflam, oozing, change in sensation
How should melanoma be managed?
Avoid excess sun/UV = sunscreen, hats, dont use sun-beds
Surgical removal with 2mm margin for histology, spread = immunotherapy, biologic therapy, radiation, chemo
TNM staging
- 0: 0.5cm margin
- 1: 1cm margin
- 2: 2cm margin
- 3: 2cm margin, Ln if SLN +ve, adjuvant targets therapy, CT staging
- 4: brain mets (surgery, RT, immunotherapy, chemo)
Recurrence/prognosis based on Breslow thickness: <0.76mm (low risk), 0.76-1.5mm (med), >1.5mm (high)
What are the risk factors for basal cell carcinoma?
UV, Hx of severe sunburn, lighter skin, radiation, arsenic, poor immune system
Describe the pathophysiology of basal cell carcinoma
Types = Superficial, infiltrative, nodular
Slow growing locally invasive malignant (rarely met) tumour of the epidermal keratinocytes.
Cumulative DNA damage leading to mutations
***most common malignant skin tumour
What are the signs and symptoms of basal cell carcinoma?
NODULAR (most common) = pearly rolled edge, small blood vessels (telangiectasia), necrotic or ulcerated centre (rodent ulcer)
SUPERFICIAL = long-standing erythematous patch, irregular, but well defined, border, when the skin is stretched there is a pearly edge
***always stretch the skin between your fingers - may reveal tumour
***most common over head/neck
How is basal cell carcinoma best managed?
Creams - 5-fluorouracil (5-FU) and imiquimod
Curettage and cautery - scraped away (curettage) and then the skin surface is sealed by heat (cautery)
Cryotherapy - freezing the BCC with liquid nitrogen
Surgical removal (common used for nodular BCC)+ 4mm (mohs surgery - high risk)
RT (not candidates for surgery)
***Increased risk of recurrence if: in size, central face (eyes, nose, lips, ears), poor defined margin, failure of Tx, immunosuppression)
***avoid future sunburn, follow up is essential as 50% will devel a 2nd one within 3y
What are the risk factors for squamous cell carcinoma?
Older age, male, fair-skinned, exposure to UV, arsenic, bowen disease, HPV, HIV/AIDS, radiation, actinic keratoses, smoking, organ transplant recipient, CLL
Outline the pathophysiology of squamous cell carcinoma
Arise from epidermal keratinocytes, can spread to tissue, bone, LNs (more malignant than basal cell)
Overall met rate of SCC is <5%
Sites associated with poorer prognosis = ear, lip, perineum, sole of foot
What are the signs and symptoms of squamous cell carcinoma and how is it Dx?
Usually begins as a dome-shaped lesion or red scaly (keratotic) patch of skin, it enlarges and the centre becomes necrotic - turning into an ulcer, crusty, bleeds easily when scraped, itchiness, painful
Ix = full skin exam, LN exam, histology (subtypes, differentiation degree, depth, dermal invasion), identify tumour margins, FNA of enlarged LN
How is squamous cell carcinoma managed?
Surgical excision (most common), dermabrasion, cryosurgery, topical chemotherapy, photodynamic surgery, ablative and non-ablative lasers, superficial RT, regional node dissection
- low risk: 4mm excision margin
- high risk: 6mm excision margin
High risk requires follow up
Outline actinic keratosis
Keratotic spot found on sun-damaged skin (classically scalp), pre-cancerous SCC - 10% risk of devel SCC in 10y, <1/1000 transform per annum
Partial thickness dysplasia
RF = immunodef, ageing, recent sun exposure, predisposing disease
S+S = PAPULE, PLAQUE, white or yellow, scaly/sand-paper, warty or horny surface, skin coloured, red or pigmented, tender or asymptomatic
Mx:
- Observation
- Sun protection = hat, long sleeved, sunscreen
- Topical Tx= 5-FU cream, diclofenac gel, imiquimod cream (Aldara)
- Further Tx = excision biopsy, cryotherapy, curettage and electrocautery, photodynamic therapy (PDT)
Describe Bowen’s disease
Precancerous common superficial form of keratinocyte cancer - derived from squamous cells, risk of malignant transformation 3-5% annually
Full thickness dysplasia
AKA = Intraepidermal squamous cell carcinoma (SCC), intraepidermal carcinoma (IEC), carcinoma in situ (SCC in situ)
RF = sun exposure, arsenic, ionising radiation, HPV, immunosuppression
S+S = irregular cobbled scaly erythematous patches of up to several cm, commonly LOWER LEGS OF ELDERLY women
Mx = observation, excision, curettage and electrosurgery, cryotherapy, 5-FU cream (cytotoxic), Imiquimod cream (inflam reaction), Photodynamic therapy (PDT - least likely to cause prob with poor healing on lower leg)
