Skin cancers Flashcards
What effect does UV have in skin cancer?
Causes mutations directly
Effect on host immune system
How does basal cell carcinoma occur?
Mutation in basal cell DNA causes proliferation
What are subtypes of basal cell carcinoma?
Nodular - pearly nodule with telangeictatic edge +/- central ulcer
Superficial - red scaly plaque
Pigmented
Morphoeic - most aggressive
What are causes of BCC?
UV exposure and immunosuppression
What is treatment of BCC?
Excision with 3-4mm margin
What is squamous cell carcinoma?
Mutation in keratinocyte gives a hyperkeratotic lesion with a crust/scale.
Can occur on damaged skin.
What does SCC look like?
Persisently ulcerated or crusted firm lesion. Locally invasive and can metastasise
What increases risk of SCC metastasis?
On lip/ear, non-UV exposed site.
Host immunosuppression
What is acitinic keratoses?
Pre-malignant variant of SCC with dysplastic intra-epidermal proliferation.
Appears as crumbly white/yellow crusts on sun-exposed sites.
What is Bowen’s disease?
Pre-malignant variant of SCC which appears as a slowly enlarging red scaly plaque with a flat edge.
Is a full-thickness carcinoma in situ.
How is SCC treated?
Surgical excision with 3-4mm margin.
How are premalignant SCC lesions treated?
Topical imiquimod or 5-fluorouracil cream; cryotherapy, photodynamic therapy.
What is melanoma?
Melanocyte mutation due to UV damage which leads to malignancy.
How does melanoma spread?
Usually radial growth phase followed by vertical invasion into lymphatics.
What are risk factors for melanoma?
Fair skin, sun exposure, >50, melanocytic or dysplastic naevi (>50), family history.
Previous melanoma
Xeroderma pigmentosum
