Basal Cell Carcinoma

Question 1

What is the most common type of cancer in the world?

Answer 1

Basal cell Carcinoma

Question 2

What are the three layers of the skin?

Answer 2

1. Epidermis
2. dermis
3. Hypodermis

Question 3

In which layer of the skin is the basal layer found?

Answer 3

epidermis

Question 4

What is the estimated lifetime risk for a BCC in white men?

Answer 4

33-39%

Question 5

what is the lifetime risk for BCC in white women?

Answer 5

23-28%

Question 6

Mutations of what two genes are associated with BCCs?

Answer 6

1) PTCH
2) TP53

Question 7

Give 5 risk factors for basal cell carcinomas:

Answer 7

1) exposure to UV radiation (esp. at a young age)
2) history of skin caner
3) fair skin prone to sunburn
4) prolonged exposure to chemical agents like arsenic
5) Gorlin syndrome

Question 8

What genetic syndrome associated with a mutation of the PTCH1 gene is associated with basal cell carcinomas?

Answer 8

Gorlin syndrome

Question 9

What is Gorlin syndrome?

Answer 9

a disease where the PTCH1 gene is mutated, leading to a high risk of BCCs and formation of benign tumours in the heart, brain and ovaries

Question 10

Where are basal cell carcinomas typically found?

Answer 10

in sun-exposed areas such as the face, forehead and scalp

Question 11

What are the three types of basal cell carcinoma?

Answer 11

1. Nodular
2. Superficial
3. Morpheaform

Question 12

What is the most common type of BCC?

Answer 12

Nodular

Question 13

What is the second most common type of BCC?

Answer 13

Superficial basal cell carcinoma

Question 14

What is the rarest type of BCC?

Answer 14

Morpheaform basal cell carcinoma

Question 15

What capillary sign is associated with nodular BCCs?

Answer 15

arborising telangiectasis

Question 16

Describe the morphology of a nodular BCC:

Answer 16

1. pearly shiny nodules with rolled edges
2. Often a depressed centre

Question 17

What is aborising telangiectasias?

Answer 17

tree-like branching capillaries found at the edge of a nodular basal cell carcinoma

Question 18

Describe the morphology of superficial BCCs:

Answer 18

plaque or patch of well defined scaly pink skin

Question 19

Describe the morphology of morpheaform BCCs:

Answer 19

poorly defined pale scales that feature linear serpentine vessels

Question 20

What instrument can be used to better view skin lesions on physical examination?

Answer 20

Dermascope

Question 21

What is the gold standard diagnostic investigation for BCCs?

Answer 21

biopsy and histological examination

Question 22

Give 4 types of biopsy that can be used to investigate BCCs:

Answer 22

1) excisional
2) incisional
3) shave
4) punch

Question 23

What two types of BCC are considered low-risk?

Answer 23

1) nodular
2) superficial

Question 24

What type of BCC is considered high-risk?

Answer 24

morphoeaform (they can have extensive local spread)

Question 25

What are 3 histological features of basal cell carcinomas?

Answer 25

1. Apoptotic cells
2. basophilic aggregations of basaloid keratinocytes with large nuclei and hardly any cytoplasm
3. Peripheral palisading of nuclei

Question 26

What is meant by the histological finding ‘peripheral palisading of nuclei’?

Answer 26

nuclei lining up at the edges of tumours

Question 27

Give 4 methods for removing low-risk BCCs:

Answer 27

1) complete surgical removal
2) electrodesiccation and curettage
3) cryotherapy
4) photodynamic therapy

Question 28

Describe electrodesiccation and curettage as a method for removing low-risk BCCs:

Answer 28

a curette is used to scrape the tumour down the dermis and then electrodesiccation applies electricity to denature the layer of the dermis down to the healthy tissue

Question 29

Give two methods for removing high-risk BCCs:

Answer 29

1) simple resection with radiotherapy
2) Moh’s micrographic surgery

Question 30

Describe Moh’s micrographic surgery as a method for removing high-risk BCCs:

Answer 30

removal of a BCC where the wound is only closed when microscopy has confirmed the entire cancer has been removed

Question 31

True or false: having a BCC increases your risk of melanoma

Answer 31

true