Common Skin Cancers Flashcards
3 layers of the skin?
epidermis
dermis
subcutaneous layer
what is the predominant cell of the epidermis?
keratinised squames
where are melanocytes found and their function?
in the epidermis
produce melanin
protect from the sun, uv radiation
give the names for 3 different cancers found on the skin.
- basal cell carcinoma
- squamous cell carcinoma
- melanocytic tumours
2 most common cancers on the epidermis?
- squamous cell carcinoma
- basal cell carcinoma
cancer of the melanocytes?
melanomas
cancer of the merkel cells?
merkel cell carcinoma
name for glandular benign tumours?
adenomas
name for malignant glandular tumours?
carcinomas
what is the common cancer for sites which have been sun exposed?
basal cell carcinomas
it is uncommon for basal cell carcinomas to metastases, so why are they an issue?
can be locally aggressive
infiltrate into dermis and subcutaneous
- infiltrate blood, nerves, bone
risk factors for basal cell carcinomas? (4)
sun, uv radiation
immunosuppressed
pale skin that burns easily
rare genetic predisposition - Gorlin syndrome and Bazex
what is Gorlin Syndrome?
- autosomal dominant
- lose function of tumour suppressor genes
= predisposed to basal cell carcinomas
results and clinical features of Gorlin Syndrome. (5)
basal cell carcinomas
- palmar pits
- skeletal abnormality
- mental retardation
- brain tumours
- odontogenic keratocysts
describe the appearance of basal cell carcinomas, from early stages to later.
appear early as nodules
- islands of basaxoid cells
- peripheral palisade
later become ulcers with rolled edges
what are the two risk types of basal cell carcinomas? describe them.
low risk
- tumour is superficial and nodular
high risk
- tumour is infiltrative, micro nodular and morphoeic
do basal cell carcinomas metastases?
its uncommon
are basal cell carcinomas more aggressive than squamous cell carcinomas?
no, SCC are more aggressive
what are the high risk sites for squamous cell carcinomas? (4)
lips
ear
perineum
may occur in mucosal sites
= sun exposed sites
what percent of squamous cell carcinomas metastases?
0.5-5%
risk factors for squamous cell carcinomas (6)
- uv rays
- radiotherapy
- immunosuppressed
- chronic ulcers can develop into scc
- new drugs for melanoma
- hydrocarbon exposure
who discovered hydrocarbon exposure?
Percivall Pott
how do squamous cell carcinomas clinically appear? how do they microscopically appear, pre-invasion and post-invasion?
nodule with ulcerated, crusted surface
actinic keratosis - pre-invasive change
- nuclei become big
- abnormally mature
invasive islands
trabecuale of squamous cells with cytological atypia
where do squamous cell carcinomas typically metastases first?
to lymph nodes
where do melanocytes derive from?
neural crest
what is the function of melanocytes?
to form melanin
protect nucleus from UV radiation
what are benign tumours of melanocytes called?
navei = moles
what are malignant tumours of melanocytes called?
melanomas
where are naveus located?
usually at the base of the epidermis - the epidermal junction
what are compound naevi?
groups of naveus cells at the epidermal junction
what are the two types of navei? describe them.
superficial
- congenital or acquired
blue naevus
- melanocytes haven’t made it to epidermis
- form masses within the dermis
4 different types of Blue Navei.
mongolian spot
navei of oto, Ito and hori
what are atypical moles?
- benign moles that may have irregular borders, different colours and appear larger
although atypical moles are benign, why are they concerning?
increase the risk of developing melanoma
- due to mutations in CDKN2A gene (p16) - tumour suppressor gene
which is the rarest skin cancer?
melanomas
risk factors for melanomas
pale skin
uv radiation
family history
congenital naevi
ABCD. describe the differences between naevus tumours and melanomas.
melanomas
- asymmetrical
- uneven borders
- colour variation
- diamete = >6mm
naevus
- symmetrical
- even borders
- uniform colour
- diameter = <6mm
how are melanomas treated?
surgery
- excise primary and lymph nodes if necessary
BRAF inhibitors
- prevent the mutation in BRAF gene
immunotherapy
- drugs to prevent tumour cells deactivating T cells
