Non-melanoma skin cancer Flashcards
What is the most common human cancer ?
Non-melanoma skin cancers
What are the 2 main types of non-melanoma skin cancers ?
Basal cell carcinoma (BCC) and Squamous cell carcinoma (SCC)
What is a BCC ?
- A common, locally invasive, keratinocyte cancer (also known as nonmelanoma cancer). It is derived from Keratinocytes from the basal layer of the epidermis.
- It is also known as a rodent ulcer
What are the risk factors for the development of BCC’s?
- Age & sex - more common in the elderly and males
- Previous BCC or other skin cancer types
- Actinic keratoses
- Repeated sunburns
- Fair skin, blue eyes and blond or red hair (burn easily)
- Inherited syndromes e.g. basal cell naevus syndrome (Gorlin syndrome) etc
- Radiation exposure
- Immunosuppression
What is Naevoid basal cell carcinoma (Gorlin’s) syndrome?
Autosomal dominant familial cancer syndrome
Major features:
- Early onset/multiple BCCs
- Palmar pits
- Jaw cysts
- Ectopic calcification falx
What mutation is associated with causing BCC’s?
- Mutations in the patched (PTCH) tumour suppressor gene, part of hedgehog signalling pathway
- Thought to be triggered by exposure to UV radiation
Describe the typical distribution of BCC’s
Mainly arise on sun-exposed sites esp the head & neck
Do BCC’s metastasise?
No but they are locally invasive
Describe the growth of BCC’s
They are slow-growing
What are the 3 main types of BCC’s to know about ?
- Nodular BCC (most common)
- Superficial BCC
- Morphoeic BCC
What are the clinical features of a nodular BCC?
- Initially appears as a well-defined flesh-coloured nodule wuth central telangectasia
- May then develop central indentation, rolled edges & telangectasia in the lesion & the surrounding skin
- Eventually may ulcerate producing a central ‘crater’
What type of skin lesion is shown in the pic ?
- Early nodular BCC
- Pic shows telangectasia, well-defined flesh coloured nodule & central indentation (right pic, slightly later sign)
What type of skin lesion is shown in the pic ?
- Later presentation of a nodular BCC
- Pic shows development of ulceration producing a central ‘crater’
What are the clinical features of a superficial BCC ?
- Irregular plaque slightly scaly
- History similar - slow growing non-healing lesion
- Telangectasia
- Multiple microerosions
What are the clinical features of a morphoeic BCC?
Waxy scar like plaque with indistinct borders
What is shown in this pic ?
A pigmented BCC - if you look closely you can see a a pearly papule in the 11 oclock positionm rolled edges, telangectasia, surface erosion & crusting in the lower aspect also seen
How are BCC’s diagnosed ?
- 1st line = Clinically
- 2nd line (definitive confirmation) = Biopsy or excision for histology/pathology
What is the treatment of nodular & morphoeic BCC’s ?
- 1st line = surgical excision - most appropriate for well-defined, nodular or morphoeic BCC’s
- 1st line = Mohs surgery - most appropariate for ill-defined, infiltrative & recurrent BCC’s
What is Mohs surgery & what is it used for ?
- Used for infiltrative, ill-defined & recurrent BCC’s. Also when skin preservation is needed
- It involves carefully exammining excised tissue under a microscope, layer by layer, to ensure complete excision is made
What is the treatment of superficial BCC’s ?
1st line = non-surgical - options include Imiquimod cream, photodyanmic therapy & cryotherapy
Note - prior to non-surgical treatment a small biopsy is done to confirm it is definitvely a BCC
What is the prognosis of BCC’s?
Most are cured. Recurrence is common (50% by 3 years)
What is cutaneous squamous cell carcinoma (SCC)?
A common type of keratinocyte cancer, or non-melanoma skin cancer. It is derived from keratinocytes from the suprabasal layers (above basal layer)
What are the risk factors for developing SCC’s?
- Age and sex: more common in elderly & males
- Previous SCC or another form of skin cancer
- Precursor lesions - Actinic keratoses or Bowens disease
- Excessive exposure to sunlight / psoralen UVA therapy
- Smoking
- Fair skin, blue eyes and blond or red hair (sun burns)
- Previous cutaneous injury, thermal burn, disease (eg cutaneous lupus, epidermolysis bullosa, leg ulcer)
- Inherited syndromes esp xeroderma pigmentosum and albinism
- Immunosupression - organ transplant recipients, cancer, HIV etc
- Other risk factors include ionising radiation
What are the features of initrinsically aged skin ?
- It is finely wrinkled
- Skin sagging or laxity
- The degrees of pigmentation in intrinsically aged skin are very mild and regular in comparison to photoaged skin.
- Aged skin tends to develop a variety of benign neoplasms, such as sebaceous hyperplasia and cherry angiomas.
- Skin cancers are less common in intrinsically aged skin than in extrinsically aged skin.
- The surface of the skin maintains youthful geometric patterns.
What are the features of extrinisically aged skin?
- Extrinsic ageing affects habitually exposed areas of the body, such as the individual’s face, neck, and arms.
- The features of photodamage include roughness, sallowness, deep wrinkling,dyspigmentation, senile purpura, telangiectasia, and the development of a variety of benign and malignant skin lesions.
- Hyperpigmented lesions include diffuse mottling, freckles, lentigines & flat seborrhoeic keratoses
- Deep wrinkles are usually found on the individual’s forehead and in the peri-orbital region.
What are the clinical features of actinic keratoses ?
- A flat or thickened papule or plaque
- White or yellow; scaly, warty or horny surface
- Skin coloured, red or pigmented
- Tender or asymptomatic
- Multiple lesions may be present
- Typically occur on sun-exposed areas e.g. temples of head
What is shown in this pic ?
- Field carcinogensis also termed field change = a biological process in which large anatomincal areas (tissue surface or within an organ) are affected by carcinogenic alterations e.g. AK’s, CIS, SSC’s
- Extensive (numerous) actinic keratoses shown
- Arrows indicate likely SCC’s
What is the treatment of field carcinogensis/change on the skin ?
Topical 5% Imiquimod cream
What are the clinical features of Bowen’s disease?
- One or more irregular scaly plaques
- Plaques are orange-red in colour
- Occur on sun-exposed sites of the ears, face, hands and esp lower legs.
Note right pic shows field change (multiple areas of sun damage, in this instance multiple lesions of bowen’s disease)
What are the clinical features of SCC’s ?
- Enlarging scaly or crusted lumps.
- Usually arise within pre-existing actinic keratosis or intraepidermal carcinoma.
- They may ulcerate
- They are often tender or painful
- Located on sun-exposed sites, particularly the face, lips, ears, hands, forearms and lower legs
Development of SCC’s where are at more risk of metastases ?
The ears & lips or mucous membranes
What are the clinical features of a keratoacanthoma ?
Said to look like a volcano or crater:
- Initially a smooth dome-shaped papule
- Rapidly grows to become a crater centrally-filled with keratin (scale)
What can SCC’s sometimes complicate ?
Chronic wounds such as leg ulcers
