Skin Cancer Flashcards
Name the following benign skin lesions [2]
- fibroepithelial polyps “skin tags”
- seborrhoeic warts/keratoses
How does UV light cause skin cancer? [3]
- At least two distinct pathways interact or converge to cause skin cancer
- Direct action of UV on target cells (keratinocytes) for neoplastic transformation via DNA damage
- Effects of UV on the host’s immune system
What are the 3 main types of skin cancer? [3]
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
Describe the pathogenesis of basal cell carcinoma [4]
- The process of creating new skin cells is controlled by a basal cell’s DNA.
- A mutation in the DNA causes a basal cell to multiply rapidly and continue growing when it would normally die.
- Eventually, the accumulating abnormal cells may form a tumour
- Rarely a PTCH gene mutation may predispose to the development of basal cell carcinoma
What are the subtypes of basal cell carcinoma? [4]
- Nodular
- Superficial
- Pigmented
- Morphoeic/Sclerotic
What are the typical features of nodular basal cell carcinoma appearance? [4]
- Nodule i.e. > 0.5cm raised lesion
- Shiny “pearly”
- Telangiectasia/blood vessels
- Telangiectasia = condition in which widened venules (tiny blood vessels) cause threadlike red lines or patterns on the skin
- Often ulcerated centrally
What are the treatment options for basal cell carcinoma? [6]
- Gold standard = Surgical excision 3-4mm margin
- Curettage and cautery
- Cryotherapy
- Photodynamic therapy
- Topical imiquimod/5-fluorouracil cream
- Mohs micrographic surgery
Describe the clinical features of squamous cell carcinoma [3]
- May occur in normal skin or in skin that has been injured (burns) or chronically inflamed
- Originates from keratinocytes
- Most SCC occur on skin that is regularly exposed to sunlight or other ultraviolet radiation
What are the pre-malignant variants of squamous cell carcinoma? [2]
- Actinic keratoses
- Bowen’s disease
What are the treatment options for squamous cell carcinoma? [3]
- Gold standard = Surgical excision 4mm margin
- Curettage and cautery
- Sun protection
What are the treatment options for the pre-malignant squamous cell carcinoma in-situ? [3]
- Topical imiquimod/5-fluorouracil cream
- Cryotherapy
- Photodynamic therapy
What is melanoma and where is it typically found? [4]
- Malignant tumour of melanocytes
- Most common in skin (but can be bowel/eye)
Describe the pathogenesis and spread of melanoma [4]
- DNA damage - mainly UV, rarely genetic
- Radial growth phase, then vertical growth
- Depth of presentation determines prognosis
- Spread via lymphatics
What are the risk factors for developing melanoma? [15]
- Genetic markers (e.g. CDKN2A mutations)
- Family history of dysplastic nevi or melanoma
- Ultraviolet irradiation
- Sunburns during childhood
- Intermittent burning exposure in unacclimatized fair skin
- Number (>50) and size mm) of melanocytic nevi
- Congenital nevi
- Number of atypical nevi (>5)
- Atypical/dysplastic nevus syndrome
- Personal history of melanoma
- High socioeconomic status
- Skin type I, Il
- Equatorial latitudes
- DNA repair defects (e.g. xeroderma pigmentosum)
- Immunosuppression
What are the sub-types of melanoma? [8]
- Superficial spreading malignant melanoma
- Nodular melanoma
- Acral melanoma
- Subungual melanoma
- Amelanotic melanoma
- Lentigo maligna
- Lentigo maligna melanoma
- Melanoma in-situ