Pathology of Skin Tumours

Question 1

What sort of biopsy is performed on potentially invasive lesions?

Answer 1

Excisional - curative as well

Question 2

What are the histological findings of solar keratoses?

Answer 2

Thicker
- Can also be thinner > atrophic
Hyper-keratotic
Slightly larger basal cells

Question 3

How is solar keratosis usually diagnosed?

Answer 3

Clinically

Question 4

What are the treatment options for solar keratosis?

Answer 4

Cryotherapy
Topical; eg:
- 5-fluoruracil
- Imiquinod
Excision biopsy if
- Concerned about invasion
- Not recurrent
Shave biopsy
- Not helpful for therapy if extensive

Question 5

What is a possible side effect of imiquinod?

Answer 5

Irritating > redness and burning

Question 6

What information should be included in the pathology report for a skin excision?

Answer 6

Location
Duration of lesion
PHx of skin lesion
Size
Clinical description
Indication for biopsy
Previous treatment

Question 7

What are the histological abnormalities of SCCs?

Answer 7

Nests

Keratin pearls

Question 8

What are the risk factors for SCC?

Answer 8

Lifetime UV exposure
Solar keratoses
Fair skin
Burn scars
Chronic ulcers
Renal/any transplant
Road workers > exposure to tar
Tobacco
Arsenic
Betel leaf chewing

Question 9

What are the bad prognostic features of SCC of skin?

Answer 9

Late presentation
Relatively thick lesion
- >6 mm depth
Large size

Question 10

What is the excision margin for SCC of skin?

Answer 10

4 mm

Question 11

What is the most frequent form of skin cancer?

Answer 11

BCC

Question 12

Where do BCCs commonly occur?

Answer 12

Sun exposed skin, esp
- Head
- Neck and trunk
- Older adults
May be multiple
Slow growing
Metastasis rare
Can be locally aggressive

Question 13

What are different types of BCCs?

Answer 13

Nodular
Superficial
Morhoeic
Basosquamous

Question 14

What are the risk factors for BCCs?

Answer 14

Fair skin
Blue eyes
Immunosuppression
Basal cell naevus syndrome
XP = genetic syndrome
Radiation

Question 15

What are the bad features of BCCs?

Answer 15

Morphoeic type - infiltrative
Basosquamous type
Perineural invasion
Incomplete excision

Question 16

What is the treatment for BCCs?

Answer 16

Excision = best
If can't excise
- Imiquinod
- Efudex
Cryotherapy - if must

Question 17

When do benign melanocytic naevi develop?

Answer 17

Some congenital

Most acquired during childhood

Question 18

What is the most common melanocytic tumour?

Answer 18

Benign melanocytic naevi

Question 19

Do benign melanocytic naevi involve mucous membranes?

Answer 19

Sometimes

Question 20

What are the macroscopic features of benign melanocytic naevi?

Answer 20

Small size
Circumscription
Symmetry

Question 21

Do benign melanocytic naevi need to be excised?

Answer 21

No
May be for
- Cosmetic reasons
- Changing
- Bleeding
- Concern about melanoma

Question 22

What are the histological features of benign melanocytic naevi?

Answer 22

Small nuclei
Melanocytes decrease in size towards base of dermal component
Absence of mitotic activity

Question 23

When are naevi a risk factor for melanoma?

Answer 23

Large numbers

Question 24

What is the risk of dysplastic naevi becoming melanoma?

Answer 24

Of single lesion transforming = low

Multiple lesions = increased risk

Question 25

What are familial dysplastic naevi syndromes?

Answer 25

Dysplastic naevus syndrome | Familial atypical multiple mole-melanoma syndrome

Question 26

What are the features of naevi in familial dysplastic naevi syndromes?

Answer 26

Multiple naevi with unusualy features | Increased risk of development of melanoma

Question 27

What are some pigmented lesions, other than naevi?

Answer 27

``` Freckles Lentigines Pigmented keratoses Basal cell and sometimes squamous cell carcinomas Vascular lesions - Haemangioma - Haematoma - Others Dermatofibroma Malignant melanoma ```

Question 28

How do you differentiate between freckles and lentigines?

Answer 28

Freckles darken with sun exposure | Lentigines don't darken with sun exposure

Question 29

What does ABCDE stand for when identifying potentially malignant lesions?

Answer 29

``` A = asymmetry B = borders - irregular C = colour D = diameter E = evolving ```

Question 30

For a possibly malignant lesion, what sort of biopsy should be performed?

Answer 30

Excision biopsy

Question 31

What is the excision margin for a melanoma?

Answer 31

Up to 10 mm

Question 32

Other than the skin, where else can melanoma occur?

Answer 32

``` Oral cavity Lip Conjunctiva Choroid Oesophagus Leptomeninges Cervix Vagina Vulva Anus ```

Question 33

Do melanomas arise in normal skin, or an existing naevus?

Answer 33

Most arise in normal skin

Question 34

What are the histological features of melanoma?

Answer 34

``` Atypical junctional proliferation Dermal invasion by atypical melanocytes - Not mature - Large, eosinophilic cytoplasm - Contain melanin - Large irregular nuclei - Prominent nucleoli - Frequent mitoses ```

Question 35

What is melanoma in-situ?

Answer 35

Malignant melanoma along dermo-epidermal junction May show pagetoid epidermal spread Don't invade dermis = Clark level 1 melanoma

Question 36

What is a red flag for a possibly malignant lesion?

Answer 36

Nail lesions that don't grow out

Question 37

What are the key tumour related prognostic factors in melanoma?

Answer 37

TNM stage | Breslow thickness

Question 38

What are host related prognostic factors in melanoma?

Answer 38

``` Age Gender Site In stage IV disease - Raised serum LDH - Poor performance status ```

Question 39

What is the relationship between Breslow thickness and risk of mortality in melanoma?

Answer 39

The higher the Breslow thickness, the higher the risk of mortality

Question 40

Is a sentinel node biopsy performed in melanoma?

Answer 40

In some cases, yes

Question 41

How is metastatic melanoma treated?

Answer 41

Surgically | Experimental chemotherapy and immunotherapy