Skin Flashcards
What are the three main types of skin cancer?
Basal-cell skin cancer (basal cell carcinoma)
Squamous cell skin cancer (SCC)
Malignant melanoma
What is the commonest form of skin cancer?
Basal cell carcinoma
What are the characteristics of basal cell carcinoma?
Slow-growing, locally invasive, malignant epidermal basal layer skin tumour
What are the risk factors for BCC?
Exposure to UV light is main aetiological factor
Fitzpatrick skin types I & II: light skin, tans poorly
Male
Mutations in PTCH, p53, ras
Albinism
Gorlin’s syndrome
Xeroderma pigmentosum
Increasing age
Previous skin cancers
Immunosuppression e.g. AIDs, transplantation
Carcinogens - ionising radiation, arsenic, hydrocarbons
What is Gorlin-Goltz syndrome?
Nevoid basal cell carcinoma syndrome
Rare autosomal dominant condition, mutation of PTCH1 gene
Early onset BCCS Broad nasal root Palmar and plantar pits Bifid ribs Hypertelorism - wide spaced eyes Calcification of faux cerebri
What are the clinical features of a typical nodular BCC?
TURP
Presence of irregular pink/skin coloured lesion
Commonly on face/neck
Telangiectasia
Ulceration
Rolled edges
Pearly edge
What are the clinical sub-types of BCC?
Nodular Superficial Morphoeic Pigmented Basosquamous
What are the features of nodular BCC?
Most cases of BCC Occur mostly on head Flesh/red coloured Well defined borders Overlying telangiectasias Rodent ulcer - central ulceration
What are the features of superficial BCC?
Erythematous plaque Mostly on trunk/limbs Slow-growing May be dry/crusted May have bluish tinge
Numerous of these may indicate arsenic exposure
What are the features of morphoeic infiltrative BCC?
Scar-like lesion or indentation Commonly occur on upper trunk or face Whitish, compact Poorly defined plaque/scar Deeply invasive
What are the features of pigmented BCC?
Difficult to distinguish from melanoma
Pigmentation due to melanin production, why it is hard
Often excised with 2mm margin as a result
What are the features of basosquamous BCC?
Rare but agressive
Increased risk of recurrence and metastasis
Differentiation towards SCC
Has macro and histopathological features of both
What surgical management is available for BCC?
Excision - wide local or Moh’s micrographic surgery for high risk lesions
Destructive - curettage, cautery, cryotherapy, carbon dioxide laser (these don’t provide histological sample, so low risk lesions only)
What non-surgical management is available for BCC?
Radiotherapy -
Adjuvant
Prevent recurrence e.g. incompletely excised margins
Recurrent BCC
High risk BCCs; and surgery not appropriate
NB risk of radiation induced BCC in those with Gorlin’s
Topical immunotherapy e.g. Imiquimod
PDT
What are the features of a high risk BCC lesion?
Size > 2cm
Site - around eyes, lips, ears
Poorly defined margins
Histological sub-type - morpoeic, infiltrative, micro nodular, basosquamous
Histological features - perineural, perivascular inv
Previous tx failure
Immunosuppression
What are the surgical excision margins for BCC?
Lesions should be excised down to subcutaneous fat to ensure entirety of skin; epidermis and dermis is included in sample
Low risk lesions - (small <2cm, well defined) margin of 4-5mm = 95% clearance
High-risk lesions - (large >2cm poorly defined) 5mm provides 83% clearance
Recurrent lesions - referral to Skin MDT, re-excision of scar 5-10mm margins or Moh’s surgery and radiotherapy
What is Moh’s surgery?
Surgical removal of tissue
Free margin removed can be less
Mapping piece of tissue, freezing and cutting, staining
Interpretation of slides, determines if any more needs to be removed
Possible reconstruction of surgical defect
What is the system used to describe a skin lesion?
A - asymmetry B - border irregularity C - colour (varies) D - diameter (greater than 6mm) E - evolving (change in shape, size or shade) F - funny looking
Describe how BCC grow
Slow growing
Locally Invading
Very rarely metastasis
What cells do BCC’s arise from?
Epidermal tumours arising from hair follicles
Describe the appearance of solar (actinic) keratoses:
On sun-exposed skin
Crumbly, yellow-white crusts
What is the risk associated with actinic keratoses?
Malignant change to squamous cell carcinoma may occur after several years
How should actinic keratoses be managed?
Cryotherapy or fluorouracil/imiquimod cream
Describe the appearance of Bowen’s disease:
Slow growing red/brown scaly plaque
How should Bowen’s disease be managed?
Cryo, topical fluorouracil, photodynamic therapy
Describe the appearance of keratoacanthoma:
Dome-shaped erythematous lesions that grow rapidly and often contain a central pit of keratin
name 3 genetic conditions associated with increased risk skin ca
- gorlins syndrome (PTCH1 gene mutation leading to increased risk nevoid BCC)
- xeroderma pigmentosa
- albinism
How should a suspected BCC be referred?
- routine referral if suspect BCC
- 2WW if concern that delay would have impact either bc or site or feature of the lesion