Common Skin Cancers

Question 1

3 layers of the skin?

Answer 1

epidermis
dermis
subcutaneous layer

Question 2

what is the predominant cell of the epidermis?

Answer 2

keratinised squames

Question 3

where are melanocytes found and their function?

Answer 3

in the epidermis

produce melanin
protect from the sun, uv radiation

Question 4

give the names for 3 different cancers found on the skin.

Answer 4

• basal cell carcinoma
• squamous cell carcinoma
• melanocytic tumours

Question 5

2 most common cancers on the epidermis?

Answer 5

• squamous cell carcinoma
• basal cell carcinoma

Question 6

cancer of the melanocytes?

Answer 6

melanomas

Question 7

cancer of the merkel cells?

Answer 7

merkel cell carcinoma

Question 8

name for glandular benign tumours?

Answer 8

adenomas

Question 9

name for malignant glandular tumours?

Answer 9

carcinomas

Question 10

what is the common cancer for sites which have been sun exposed?

Answer 10

basal cell carcinomas

Question 11

it is uncommon for basal cell carcinomas to metastases, so why are they an issue?

Answer 11

can be locally aggressive
infiltrate into dermis and subcutaneous
- infiltrate blood, nerves, bone

Question 12

risk factors for basal cell carcinomas? (4)

Answer 12

sun, uv radiation

immunosuppressed

pale skin that burns easily

rare genetic predisposition - Gorlin syndrome and Bazex

Question 13

what is Gorlin Syndrome?

Answer 13

• autosomal dominant
• lose function of tumour suppressor genes
  = predisposed to basal cell carcinomas

Question 14

results and clinical features of Gorlin Syndrome. (5)

Answer 14

basal cell carcinomas
- palmar pits
- skeletal abnormality
- mental retardation
- brain tumours
- odontogenic keratocysts

Question 15

describe the appearance of basal cell carcinomas, from early stages to later.

Answer 15

appear early as nodules
- islands of basaxoid cells
- peripheral palisade
later become ulcers with rolled edges

Question 16

what are the two risk types of basal cell carcinomas? describe them.

Answer 16

low risk
- tumour is superficial and nodular

high risk
- tumour is infiltrative, micro nodular and morphoeic

Question 17

do basal cell carcinomas metastases?

Answer 17

its uncommon

Question 18

are basal cell carcinomas more aggressive than squamous cell carcinomas?

Answer 18

no, SCC are more aggressive

Question 19

what are the high risk sites for squamous cell carcinomas? (4)

Answer 19

lips
ear
perineum
may occur in mucosal sites

= sun exposed sites

Question 20

what percent of squamous cell carcinomas metastases?

Answer 20

0.5-5%

Question 21

risk factors for squamous cell carcinomas (6)

Answer 21

• uv rays
• radiotherapy
• immunosuppressed
• chronic ulcers can develop into scc
• new drugs for melanoma
• hydrocarbon exposure

Question 22

who discovered hydrocarbon exposure?

Answer 22

Percivall Pott

Question 23

how do squamous cell carcinomas clinically appear? how do they microscopically appear, pre-invasion and post-invasion?

Answer 23

nodule with ulcerated, crusted surface

actinic keratosis - pre-invasive change
- nuclei become big
- abnormally mature

invasive islands
trabecuale of squamous cells with cytological atypia

Question 24

where do squamous cell carcinomas typically metastases first?

Answer 24

to lymph nodes

Question 25

where do melanocytes derive from?

Answer 25

neural crest

Question 26

what is the function of melanocytes?

Answer 26

to form melanin protect nucleus from UV radiation

Question 27

what are benign tumours of melanocytes called?

Answer 27

navei = moles

Question 28

what are malignant tumours of melanocytes called?

Answer 28

melanomas

Question 29

where are naveus located?

Answer 29

usually at the base of the epidermis - the epidermal junction

Question 30

what are compound naevi?

Answer 30

groups of naveus cells at the epidermal junction

Question 31

what are the two types of navei? describe them.

Answer 31

superficial - congenital or acquired blue naevus - melanocytes haven't made it to epidermis - form masses within the dermis

Question 32

4 different types of Blue Navei.

Answer 32

mongolian spot navei of oto, Ito and hori

Question 33

what are atypical moles?

Answer 33

- benign moles that may have irregular borders, different colours and appear larger

Question 34

although atypical moles are benign, why are they concerning?

Answer 34

increase the risk of developing melanoma - due to mutations in CDKN2A gene (p16) - tumour suppressor gene

Question 35

which is the rarest skin cancer?

Answer 35

melanomas

Question 36

risk factors for melanomas

Answer 36

pale skin uv radiation family history congenital naevi

Question 37

ABCD. describe the differences between naevus tumours and melanomas.

Answer 37

melanomas - asymmetrical - uneven borders - colour variation - diamete = >6mm naevus - symmetrical - even borders - uniform colour - diameter = <6mm

Question 38

how are melanomas treated?

Answer 38

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