Cancer

Question 1

What is melanoma?

Answer 1

Melanoma is a type of malignant cancer that arises from the melanocyte layer of the skin, normally situated at the basal layer of the epidermis (inner most layer).

Question 2

Melanoma occurs when melanocytic stem cells undergo a …. and ….

Answer 2

genetic transformation and proliferate uncontrollably.

Question 3

What do melanocytes produce?

Answer 3

Melanin

Question 4

Melanin function

Answer 4

Melanin is a protein that helps protect against harmful ultraviolet radiation exposure.

Question 5

Why is damage caused by UV exposure more likely in white skin compared to dark-brown or black skin?

Answer 5

Melanocytes are found in equal numbers in different skin tones. However, darker skin produces more melanin.

Question 6

In situ meaning

Answer 6

The tumour is confined to the epidermis

Question 7

Invasive meaning

Answer 7

The tumour has spread into the dermis

Question 8

Metastatic meaning

Answer 8

The tumour has spread to other tissues

Question 9

medical name for moles

Answer 9

benign melanocytic naevi

Question 10

medical name for freckles

Answer 10

lentigines and phelides

Question 11

When melanocytes grow in a non-cancerous way, they result in…

Answer 11

moles and freckles

Question 12

What are the 4 common subtypes of melanoma?

Answer 12

Superficial spreading melanoma (most common), nodular melanoma, lentigo melanoma, acral lentiginous melanoma.

Question 13

Risk factors of melanoma

Answer 13

History of skin cancer, melanoma, or atypical naevi
Family history of melanoma
Pale skin (Fitzpatrick skin type I and II)
Red or light-coloured hair
High freckle density
Light coloured eyes
History of sunburn
Sun exposure or tanning bed exposure
Large amounts of moles
Increasing age
Immunosuppression
Outdoor occupation
Genetic syndromes with skin cancer predisposition (for example, xeroderma pigmentosum)

Question 14

What is the name for a melanoma with no pigment?

Answer 14

Amelanotic melanoma

Question 15

What is the ABCDE criteria that is used to describe features that most melanomas have?

Answer 15

Asymmetrical shape
Border irregularity, including poorly defined margins
Colour change and variation
Diameter of the mole (most melanomas are >6mm)
Evolving (such as changing in size, shape or colour)

Question 16

What is seborrhoeic ketatoses?

Answer 16

A common and benign class of lesion that can score highly on the ABCDE criteria are seborrhoeic keratoses (aka seborrhoeic warts).

Question 17

Dermoscopic features of melanomas

Answer 17

-atypical network (white or pigmented)
-aggregated black or brown dots and globules
-features specific to the site of the melanoma (e.g. parallel pattern on palms and soles).

Question 18

What is Breslow thickness?

Answer 18

Measures the thickness of invasive melanoma in millimetres from the granular cell layer to the deepest tumour cell.

Question 19

What does a sentinel lymph node biopsy test for?

Answer 19

Spread of cancer

Question 20

What is the medical management for malignant melanoma?

Answer 20

-targeted therapy such dabrafenib and vemurafenib may be used in patients with BRAF V600 mutation-positivity

• immunotherapy such as nivolumab plus ipilimumab

-chemotherapy for advanced melanoma not responsive to treatment

Question 21

All suspicious pigmented lesions should undergo…

Answer 21

excisional biopsy for histology

Question 22

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

Answer 22

Basal cell carcinoma

Question 23

What is basal cell carcinoma?

Answer 23

It is a non-melanoma form of skin cancer that develops very slowly in the upper layers of the skin and rarely metastasises.

Question 24

What are the 3 layers of the skin?

Answer 24

The epidermis: the thin outer portion of the skin made up of the inner basal layer, the prickle cell layer, the granule cell layer and the keratinised squamous layer (Figure 1)
The dermis: the thicker inner portion of the skin which consists of connective tissue and contains nerves, vessels and sweat glands
The hypodermis: the innermost layer that fuses with the dermis and consists of adipose tissue and sweat glands.

Question 25

BCCs develop from mutations, usually in the … and … genes affecting the …. layer

Answer 25

BCCs develop from mutations, usually in the PTCH and TP53 genes, affecting the basal cell layer of the epidermis.

Question 26

Risk factors for the development of BCC

Answer 26

Exposure to UV radiation, especially acute intermittent exposure at a young age
Fair skin prone to sunburn that does not tan easily
Ionising radiation
Repeated micro-injuries
Scars/chronic ulcers
Prolonged exposure to chemical agents (i.e. arsenic)
Gorlin syndrome
Immunosuppression
History of skin cancer

Question 27

what 3 main types can BCCs be categorised into?

Answer 27

nodular, superficial and morpheaform (aka sclerosing or infiltrating)

also pigmented BCC

Question 28

Common histological findings of all BCCs

Answer 28

Basophilic aggregations of basaloid keratinocytes with large nuclei and scant cytoplasm
Clefts of tumour tissue
Peripheral palisading of nuclei
Apoptotic cells

Question 29

what is the most common type of BCC?

Answer 29

nodular

Question 30

management options for BCC

Answer 30

surgical excision, ED&C (electrodesiccation and curretage), topical treatments (5-fluorouracil) , cryotherapy and photodynamic therapy