Skin 1
What is the most common skin malignancy in Australia? What cell type does it come from?
Basal cell carcinoma from keratinocytes
What is the most common skin cancer among YOUNGER Australians? What cell type does it come from?
Malignant melanoma from melanocytes
Where do SCCs metastasise to?
Lymph nodes
Lungs
Liver
Brain
Bone
What is an actinic keratosis?
Precursor lesion to SCC - scaly papule
What is the mutation involved in malignant melanoma?
BRAF V600E
List some prognostic factors of melanoma
Mitotic rate
Ulceration
Breslow depth
Invasion into vessels, lymphatics
How could you differentiate between an early SCC and an invasive SCC clinically?
Invasive SCCs are non-healing and bleed easily, may have ulceration
Which skin cancer is described as having an excellent prognosis but will progressively grow if not treated?
BCC
List the functions of the epidermis
Waterproofing and protection against trauma
Melanocytes produce melanin
Epidermal DCs for APCs, immune function
Sensation - touch receptors e.g. Merkels
What are the clinical features of melanoma?
ABCDE
Asymmetrical
Borders irregular
Colour is variable
Diameter >6mm
Evolving in size, shape, colour
Stratum corneum
Stratum lucidum -
Stratum granulosum -
Stratum spinosum - DCs
Stratum basale - Merkel's cells
Define 'Breslow depth'
Distance between the top of the stratum granulosum to the deepest tumour cell
Most important prognostic factor and guides surgical margins for melanoma
Describe the clinical features of a basal cell carcinoma
Pearly papule
Rolled borders
Telangiectasia
Umbilication
Excisional biopsy with 2mm margins
Histopathology determines Breslow thickness which guides surgical margin
Definitive surgical margin based on Breslow thickness
Sentinel lymph node biopsy if Breslow <0.8mm with ulceration or >0.8mm.
If SLN positive --> PET for distant mets
Explain Clark Level
Depth of melanoma as it grows in the skin
5 levels (1 - epidermis, 2 - papillary dermis, 3 - touching reticular dermis, 4 - into reticular dermis, 5 - into subcutaneous tissue)