Skin Cancer Flashcards
Name and describe two benign skin lesions
- Fibro epithelial polyps “skin tags”
* Seborrhoeic warts/keratoses
What two pathways interact 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 three main skin cancer types?
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
What level of infiltration occurs in a squamous cell carcinoma?
Epidermis
What layer of infiltration occurs in a basal cell carcinoma?
Epidermis and dermis
Explain the pathogenesis of a basal cell carcinoma
- 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
- The accumulating abnormal cells may form a tumour
Which gene mutation may predispose to a basal cell carcinoma?
PTCH
Where is the common site of basal cell carcinoma?
80% found on the head and neck/UV exposed sites
What is the appearance of a nodular basal cell carcinoma?
- Shiny
- Nodule i.e. raised lesion>0.5cm
- Telangectasia/blood vessels
- Often ulcerated centrally
What are the subtypes of basal cell carcinoma?
- Nodular
- Superficial
- Pigmented
- Morphoeic/sclerotic
What is the appearance of a morphoeic/sclerotic basal cell carcinoma?
- Depressed area of skin
* Still shiny with increased blood vessels
What is the gold standard treatment of basal cell carcinoma?
Surgical excision with a 3-4mm margin
What are the treatments for basal cell carcinoma?
- Surgical excision 3-4mm margin
- Curettage and cautery
- Cyrotherapy
- Photodynamic therapy
- Topical imiquimod/ 5- fluorouracil cream
- Mohs micrographic surgery
What cell do squamous cell carcinomas originate from?
Keratinocytes
What are the pre-malignant variants of squamous cell carcinoma?
- Actinic keratoses
* Bowen’s disease