Skin Cancer Flashcards
What do you ask if someone presents with a new lesion?
- Has it grown, changed colour or shape?
- Need to know about risk factors - skin type, immunosuppressed, FH, sunbed use, smoker
- Cigarette smoking»_space;» squamous cell skin carcinoma
What are risk factors for basal cell carcinoma?
- Chronic UV light exposure
- Fitzpatrick Skin Type 1 and 2
- Chemicals
- Immunosuppression
- Genetic - Gorlin’s syndrome
What are risk factors for squamous cell carcinoma?
- Chronic UV light exposure
- Fitzpatrick Skin Type 1 and 2
- Chemicals
- Immunosuppression
- Cigarette smoking
- Chronic ulcers
- Genetic - xeroderma pigmentation
What is Gorlin’s Syndrome?
A genetic condition resulting in the mutation of Tumour Suppressor Gene PTCH1. It results in the development of multiple early onset BCCs.
What is Xeroderma Pigmentosum?
Autosomal recessive condition resulting from a deficit in DNA repair. This results in extreme sun sensitivity and a predilection for skin cancer.
What are the Fitzpatrick Skin types?
- Type I: always burns, never tans, very pale white skin, blue/hazel eyes, red/blonde hair
- Type II: usually burns, tans poorly, pale white skin, blue eyes
- Type III: tans after initial burn, darker white skin
- Type IV: tans easily, burns minimally, light brown skin
- Type V: tans darker, brown, rarely burns, brown skin
- Type VI: always tans darkly, never burns, dark brown/black skin
How would you examine if you suspected a malignant lesion?
Check the whole body for other lesions and evidence of photodamage. If suspecting a malignant lesion, then check for evidence of metastases, particularly draining lymph nodes and hepatomegaly.
Describe squamous cell carcinoma
Primary cutaneous SCC is a malignant tumour arising from the keratinocytes of the epidermis and its appendages. Tumours can invade locally and have the potential to metastasise to other areas of the body. SCCs can arise de novo, but can also develop from precursor lesions.
How does SCC present?
- SCCs usually present as solitary, firm, erythematous papules arising from indurated nodular lesions. Commonly they have crusted or hyperkeratotic surfaces.
- Occasionally lesions are ulcerated and rarely there are verucous forms which can be mistaken for viral warts.
- Lesions are often painful and grown rapidly (over a few weeks to a couple of months).
- Common sites are the face, scalp and back of hands
- They are rare <60yrs but patients on immunosuppressive drugs are at particular risk and may present earlier.
What may histology of SCC show?
- Reduced stroma with lymphocytes
- Nests of tumour cells
- Keratinous pearls
What genes are thought to be involved in SCC?
Mutations of BCL2 and RAS genes are believed to contribute to the pathogenesis of SCC. Alterations in intracellular signal transduction pathways, including the epidermal growth factor receptor (EGFR) and cyclo-oxygenase (COX), have also been shown to play a role in the development of SCC.
What are the features of actinic/solar keratoses?
- Multiple lesions
- Often head and neck
- Not indurated, ulcerated or painful
- Dysplastic keratinocyte cells as base of epidermis
- Ideal treatment is 5% 5-fluorouracil (Efudix) cream
What are the features of Bowen’s disease?
- Single plaque
- Often legs
- Not indurated, ulcerated or painful
- Full thickness dysplasia of epidermis
- Risk of progression to SCC is 1/25
- Ideal treatment is cryotherapy
What clinical features of SCC suggest a poorer prognosis?
- Tumours >2cm in size are twice as likely to metastasise
- Lesions on the lip or ear
- Immunosuppression (tumours histologically more aggressive)
What histological features of SCC suggest a poorer prognosis?
- Invasion >4mm
- Perineural invasion
- Nuclear atypia (poorly differentiated cells) have a poorer prognosis with increased risk of metastasis
