Skin cancer

Question 1

what skin cancer makes up 75% of NMSDs

Answer 1

BCC

Question 2

BCC risk factors?

Answer 2

previous skin cancer (any kind)
UV exposure: repeated acute sunburn
genetic susceptibility: skin type I and II, Gorlin syndrome, albinism, xeroderma pigmentosum
Immunosuppression

Question 3

can BCC metastasise?

Answer 3

v rarely

Question 4

why do BCCs need to be removed?

Answer 4

locally invasive

Question 5

subtypes of BCC?

Answer 5

nodular (most common; ‘rodent ulcer’): raised pearly border with visible telangiectasia. Central ulceration can develop
Superficial: scaly plaque with raised ‘whipcord’ margin
Morphoeic (can be infiltrative; more difficult to manage): atrophic, scar-like

Question 6

BCC

1) typical location?
2) rate of growth?
3) appearance?
4) colour?
5) pain?

Answer 6

1) areas of sun exposure (head and back), also back/ chest (areas of sunburn)
2) slow growing (months - years)
3) plaque, nodule or non-healing ulcer
4) skin, pink or pigmented
5) painless

Question 7

type of biopsy for BCC diagnosis?

Answer 7

usually
excisional for nodular
punch for superficial

Question 8

when is clinical diagnosis and management without biopsy appropriate in BCC?

Answer 8

superficial types at low risk sites (not head and neck)

Question 9

Rx of BCC

1) nodular
2) superficial
3) difficult sites/ infiltrative types

Answer 9

1) surgical excision mainstay
2) imiquimod, liquid nitrogen, PDT, 5-FU
3) Mohs

Question 10

BCC prognosis

Answer 10

treatment curative in most cases

increases risk of recurrence and other skin cancer types

Question 11

risk factors for SCCs?

Answer 11

age and gender (elderly males)
UV exposure (chronic sun exposure > photodamage)

Question 12

SCC precursors differencce histologically?

Answer 12

Actinic keratosis: partial thickness keratinocyte dysplasia, no invasion

Bowen’s disease: full thickness keratinocyte dysplasia + invasion

Question 13

histological definition of SCC?

Answer 13

unregulated proliferation of keratinocytes within the epidermis with invasion into the dermis

Question 14

T/F: mets are common in SCC

Answer 14

false (5% risk)
is locally invasive
mets uncommon (occurs in larger and poorly differentiated tumours, immunosuppressed pts)

Question 15

T/F: most SCCs are well differentiated

Answer 15

true (low risk)

Question 16

histopathological subtypes of SCC?

Answer 16

cutaneous horn

Carcinoma cuniculatum.

Question 17

presentation of SCCs?

Answer 17

fairly fast growing (weeks- months) hyperkeratotic lump, may be painful/ tender. Risk of bleeding.

Question 18

diagnosis of SCC?

Answer 18

excisional biopsy

Question 19

mainstay of treatment for SCC?

Answer 19

surgical excision

Question 20

Rx metastatic SCC?

Answer 20

conventional surgery + radio/ chemo

Question 21

MM precursor lesions?

Answer 21

benign melanocytic naevi
congenitcal melanocytic naevi
dysplastic (atypical) naevi

Question 22

subtypes of MM?

Answer 22

superficial spreading
acral/ mucosal lentiginous
lentigo maligna
nodular

Question 23

growth phases of MM?

significance of this

Answer 23

radial growth phase (within epidermis) 
vertical GP (dermal invasion)

only lesions with a VGP can metastasise

Question 24

which of the subtypes of MM is in which growth phase?

Answer 24

lesions with RGP +/- VGP 
 - superficial spreading
 - acral/ mucosal lentiginous
 - lentigo maligna
lesions with VPG only 
 - nodular