3: Pathology of pigmented lesions

Question 1

Which aspects of the skin can tumours arise from?

Answer 1

Epidermis

Melanocytes

Dermis

Appendages

Lymphoid elements

Question 2

What does in-situ mean in relation to invasive?

Answer 2

Limited to epidermis only

Question 3

From which embryological structure do melanocytes come from?

Answer 3

Neural crest

Question 4

What are precursor melanocytes called?

Answer 4

Melanoblasts

Question 5

In which epidermal layer are melanocytes found?

Answer 5

Basal layer

Question 6

What is the ratio of melanocytes : basal keratinocytes?

Answer 6

1 : 10

Question 7

____ transfer melanin to ___ through their ___ processes.

Answer 7

Melanocytes , keratinocytes , dendritic

Question 8

What does melanin protect keratinocytes from?

Answer 8

UV radiation

Question 9

What is the technical names for freckles?

Answer 9

Ephilides

Question 10

What are freckles?

Answer 10

Patchy increases in melanin production

Question 11

When do freckles appear?

Answer 11

After UV exposure

Question 12

What are actinic lentigines (sing. lentigo)?

Answer 12

“Liver spots”

Question 13

What is the technical name for a birthmark?

Answer 13

Melanocytic naevi

Question 14

If a melanocytic naevi is big, what is at risk of turning into?

Answer 14

Melanoma

Question 15

What are the two main types of naevi?

Answer 15

Congenital and acquired

Question 16

What term, describing benign abnormal growth, can be used instead of naevi?

Answer 16

Hamartoma

Question 17

What are the three terms used to describe acquired melanocytic naevi as they sink into the dermis over time?

What does each stage look like?

Answer 17

Junctional - flat and circular

Compound - raised

Intradermal - raised and hairy

Question 18

What can dysplastic naevi turn into?

Answer 18

Melanoma

Question 19

The two atypical naevi - ___ naevi and ___ naevi - are totally (benign / malignant).

Answer 19

halo , blue

benign

Question 20

Which kind of rare naevi occur in children and resemble melanoma, but are actually benign?

Answer 20

Spitz naevi

Question 21

If you are unsure whether or not a lesion is a benign naevus or a malignant melanoma, refer to?

Answer 21

Dermatology

Question 22

What can arise from dysplastic naevi?

Answer 22

Malignant melanoma

Question 23

Malignant melanoma is more common in (men / women),

Answer 23

women

Question 24

What is the biggest risk factor for developing malignant melanoma?

Answer 24

UV exposure - sun, sunbeds

Question 25

Malignant melanoma risk is also tied to a person's \_\_\_\_.

Answer 25

**genetics**

Question 26

Where can malignant melanomas arise?

Answer 26

**Literally anywhere**

Question 27

What are some signs which should make you suspect malignant melanoma in a skin lesion?

Answer 27

**ABCDE** E being changes in shape, size, bleeding, ulceration, new nodules...

Question 28

What are the four types of melanoma?

Answer 28

**Superficial spreading** **Acral / mucosal** **Lentigo maligna** **Nodular**

Question 29

Where do superficial spreading melanomas appear?

Answer 29

**Trunk and limbs**

Question 30

Where do **acral** **melanomas appear?**

Answer 30

**Fingers / toes** + **nails**

Question 31

What is acral melanoma often mistaken for?

Answer 31

**Nail trauma**

Question 32

Where does **lentigo maligna melanoma** appear? Why?

Answer 32

**Face / neck / scalp** Sun damage

Question 33

What is lentigo maligna a complicated name for?

Answer 33

**Melanoma** arising for actinic/solar lentigo - macules of pigment and melanocytes caused by UV damage

Question 34

What is the difference between **lentigo maligna** and **lentigo maligna melanoma**?

Answer 34

**Lentigo maligna** is confined to the epidermis and hasn't started to invade yet **Lentigo maligna melanoma** is invading

Question 35

What are the two phases of malignant melanoma growth?

Answer 35

**Radial / Horizontal growth phase** - tumour is in-situ **Vertical growth phase** - tumour is invading dermis

Question 36

Only melanomas in the (**horizontal / vertical**) growth phase can metastasise.

Answer 36

**vertical**

Question 37

What type of melanoma is considered more aggresive because it goes straight into the vertical growth phase?

Answer 37

**Nodular melanoma**

Question 38

What does the Breslow thickness measure?

Answer 38

**Distance from deepest part of tumour to the granular layer**

Question 39

Apart from a high Breslow thickness, what are two another indicator of poor melanoma prognosis?

Answer 39

**Bleeding** **Ulceration**

Question 40

By which means can melanoma spread around the body?

Answer 40

Lymph nodes \> Lymphatics Blood vessels

Question 41

Where can metastatic melanoma end up?

Answer 41

**Heart** **Lungs** **Liver** **GI tract** **Brain** **Skin**

Question 42

If a melanoma is less than 1mm thick, what margin of skin is excised around it? \> 1mm?

Answer 42

**1cm** **2cm**

Question 43

What else can be removed along with the malignant melanoma itself?

Answer 43

**Lymph nodes**

Question 44

How is advanced malignant melanoma treated?

Answer 44

**Chemotherapy** **Immunotherapy**

Question 45

Mutations of which gene are responsible for malignant melanoma on sun-exposed skin?

Answer 45

**B-RAF**

Question 46

Which type of gene is B-RAF?

Answer 46

**Oncogene**

Question 47

The proto-oncogene for B-RAF is very **(strong / weak)**.

Answer 47

**weak**

Question 48

Which pathway is involved in malignant melanoma on sun-exposed skin?

Answer 48

**RAS / RAF / MAPK pathway**

Question 49

Which drug can be used to block the RAS / RAF / MAPK pathway to treat malignant melanoma?

Answer 49

**Imatinib**