Skin Cancer

Question 1

What are three common types of skin cancer?

Which type is most common?

Answer 1

1) basal cell carcinoma
2) squamous cell carcinoma
3) malignant melanoma

types 1 and 2 make up 90% of skin cancer, basal cell carcinoma is the most common form

Question 2

Skin cancer has a pre-cancerous lesion - what is it?

Answer 2

atinic keratosis (an erythematous lesion)

• atinic refers to solar radiation

Question 3

What are risk factors for skin cancer?

Answer 3

• age (because damage to skin from sunlight is cumulative)

- lack of melanin (which is protective) = aka fair skin

Question 4

Why is early detection important for skin cancer?

Answer 4

With early detection and treatment the cure rate for skin cancer is 95%.

Question 5

What causes skin cancer?

Answer 5

(gene mutation)

• excessive exposure to sunlight (UVA)
• skin damage is cumulative
• tanning beds cause damage!

Question 6

What are nevi?

Answer 6

skin tags or moles, they are benign tumours and in most cases they stay benign

Question 7

How is skin cancer (all types) treated?

Answer 7

• early detection

- surgical excision

Question 8

What is the cell of origin in basal cell carcinoma?

Answer 8

basal cells in the epidermis

Question 9

What is the prognosis for basal cell carcinoma and give three reasons why?

Answer 9

good prognosis because:

• slow progression
• usually doesn’t metastasize (there is local invasion and destruction though)
• lesion is usually uniform (dome shaped/nodular lesion) - this means it is easier to diagnose and excise

Question 10

In basal cell carcinoma, where are lesions normally?

Answer 10

exposed areas of the skin (head, neck, face)

Question 11

How is basal cell carcinoma diagnosed?

Answer 11

biopsy - but excise the whole thing and you are then also treating it

Question 12

What is the cell of origin in squamous cell carcinoma?

Answer 12

keratinocytes in the epidermis

Question 13

In squamous cell carcinoma where are lesions normally?

Answer 13

exposed skin (face, head and neck)

Question 14

In addition to a different cell of origin, what are some other differences squamous cell carcinoma has from basal cell carcinoma?

Answer 14

• faster growing
• poorly defined, appearance can vary (makes diagnosis, detection harder - can be a nodule, ulcer, papule)
• may infiltrate local structures (move into deeper layers)
• metastasis to local lymph nodes, can then metastasize via the blood

Question 15

What is the prognosis for squamous cell carcinoma?

Answer 15

if detection and intervention early, the prognosis is good but if left untreated it can cause death

Question 16

What is the cell of origin in malignant melanoma?

Answer 16

melanocytes

Question 17

Why is malignant melanoma the worst form of skin cancer we talked about?

Answer 17

• rapidly progressive
• metastasizes quickly and easily
• can be fatal if untreated

Question 18

Where do lesions occur in malignant melanoma?

Answer 18

exposed and non-exposed skin

Question 19

Where does malignant melanoma metastasize to?

Answer 19

brain, bone, liver, lungs

Question 20

What is a particular risk for malignant melanoma?

Answer 20

intense exposure to sunlight

Question 21

What types of changes to lesions are indicative of skin cancer?

Answer 21

• change in size (doubling in 3-8 months)
• change in colour
• irregular border
• pruritus
• bleeding
• crusting
• ulceration

Question 22

How might you educate a patient about changes to look for in skin lesions?

Answer 22

use the ABCDE acronym:

A - asymmetry
B - borders (irregular borders)
C - colour (more than one colour, changes in colour)
D - diameter (changes in size)
E - elevation