Skin cancer Flashcards
Pathogeneis of skin cancer
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
Main skin cancer types
- basal cell carcinoma
- squamous cell carcinoma
- malignant melanoma
Basal cell carcinoma
most common tyep of skin cancer
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
PTCH gene mutation may predispose
basal cell caricnoma subtypes
- nodular
- superficial
- pigmented
- morphoeic/sclerotic
What type of BCC is this? and describe it
- Nodule ie > 0.5cm raised lesion
- Shiny “pearly”
- Telangectasia / blood vessels
- Often ulcerated centrally
nodular
What type of skin cancer is this? and describe it
Superficial
- sits on surface
- look at whole picture
- evidence of sun damage
What type of BCC is this? and decribe
Pigmented
- darker skin types
- raised
- pearly
- erythema at base
What type of BCC is this? and desccribe
- white shiny plaque
- pink
- subtle BVs
- less defined edges
Treatment - basal cell carcinoma
- Gold standard – Surgical excision 3-4mm margin
- Curettage and cautery
- Cryotherapy
- Photodynamic therapy
Squamous cell carcinoma
- may occur in normal skin or in skin that has been injured (burns) or chronically inflammated
- originates from keratinoctes
- 2nd commonest skin cancer
- skin regularly exposed to sunlight
Describe thiis squamous cell carcinoma
- rough
- scaily
- ulcerate
- no broken BVs
Treatment of squamous cell carcinoma
- Gold standard – Surgical excision 4mm margin
- Curettage and cautery
Pre-malignant /squamous cell in-situ
- Topical imiquimod / 5-fluorouracil cream
- Cryotherapy
- Photodynamic therapy
- Sun protection
Melanoma definition
malignant tumour or melanocytes
Melanoma skn cancer risk factors
- UV exposure (sunburn)
- Genetic (mutatin in CDKN2a)
- sporadic V600e (mtation of vailne by glutamate at 600), overactive BRAF sigalling
Types of melanoma
- superficial spreading
- nodular
- lentigo melanoma