Clinical: Melanoma, Non Melanoma and Benign Skin Lesions

Question 1

What is the most common non-melanoma skin cancer?

Answer 1

Basal Cell Carcinoma

Question 2

What are the 3 types of basal cell carcinomas?

Answer 2

Superficial, Nodular and Infiltrative

Question 3

How does BCC arise?

Answer 3

Derived from immature pluripotent epidermal cells and is composed of cells with similarities to basal cell layer of epidermis and appendages

Question 4

Who does BCC commonly affect?

Answer 4

Middle aged, sun exposed patients

Question 5

Is BCC slow/fast growing and locally/widely destructive?

Answer 5

Slow growing and locally destructive. May ulcerate.

Question 6

How can BCC kill?

Answer 6

By invading the eye and damaging the brain

Question 7

What is the typical transformation of BCC from an early lesion to a developed one?

Answer 7

Early: pale, translucent papules or nodules with overlying superficial telangiectasis.
Late: ulcerated with raised, rolled edge

Question 8

What does a superficial BCC look like?

Answer 8

• Brown plaques with raised thread like edge

- Tissue needs to be resected

Question 9

What does an infiltrative BCC look like?

Answer 9

• Morphoeic causes destruction if neglected
• Ill defined edge and slow growing
• May infiltrate tissue widely

Question 10

What does a nodular BCC look like?

Answer 10

• Well defined nodule, looks stuck on

- Shiny and pearly

Question 11

What is the best management for BCC?

Answer 11

• Early nodular BCC is best excised
• At difficult lesions around the eyes- Mohs’ micrographic surgery
• Clearance of more than 90% of tumours should be achieved
• Cryotherapy for small, localised, low risk lesions

Question 12

What does squamous cell carcinoma arise from?

Answer 12

Epidermal keratinocytes

Question 13

Where does a patient typically present with SCC?

Answer 13

On sun exposed areas such as bald scalp, tops of ears, face and back of hands

Question 14

When does SCC behave most aggressively?

Answer 14

• In immunocompromised patients

- On the lips and ears

Question 15

What is the first choice management for SCC?

Answer 15

Complete surgical excision

Question 16

What is the cure rate for most SCC if the excision is cut with a 3-4mm margin?

Answer 16

90-95% for most SCC

Question 17

What can be given to patients with high risk for further SCCs?

Answer 17

Systemic retinoids

Question 18

What is Actinic Keratosis?

Answer 18

Hyperkeratotic Erthythematous lesions arising on chronically sun exposed areas

Question 19

What is the risk of progression Actinic Keratosis to SCC?

Answer 19

0.1%

Question 20

Does SCC always have to arise from Actinic Keratosis?

Answer 20

No, it can arise de-novo

Question 21

What may indicate a transformation of Actinic Keratosis to SCC?

Answer 21

Increase in size, ulceration, bleeding, pain or tenderness

Question 22

What is the histology of Actinic Keratosis?

Answer 22

Moderate squamous cell dysplasia. Not as dysplastic as Bowen’s disease.

Question 23

What is Bowen’s disease?

Answer 23

In situ, SCC on lower leg of elderly woman

Question 24

What can Bowen’s disease mimic?

Answer 24

Inflammatory diseases

Question 25

What is the presentation of Bowen's disease?

Answer 25

Slow growing, well demarcated, scaly, erythematous plaque

Question 26

What may be difficult to distinguish Bowen's from?

Answer 26

Superficial BCC

Question 27

What does Bowen's disease often co-exists with?

Answer 27

Venous stasis

Question 28

What is the % chance of Bowen's disease developing into SCC?

Answer 28

3%

Question 29

What is the histology of Bowen's disease?

Answer 29

Crowding, hyperkeratosis, parakeratin

Question 30

How is Bowen's disease managed?

Answer 30

Non surgical procedures are often preferred. Incisional biopsy to confirm diagnosis.

Question 31

What is keratoacanthoma?

Answer 31

A benign squamous tumour, difficult to distinguish from SCC as it clinically and histologically similar.

Question 32

How does keratoacanthoma develop?

Answer 32

Rapid growth over weeks-moths then spontaneous resolution

Question 33

What does keratoacanthoma look like?

Answer 33

Isolated dome shaped nodule with central keratin plug

Question 34

What is the most common type of cutanous T cell lymphoma?

Answer 34

Mycosis Fungiodes

Question 35

"scaly rash (like psoriasis) tumour that can on for 20-30 years"

Answer 35

Mycosis Fungiodes (cutaneous lymphoma)

Question 36

What is the defective gene copy in freckles?

Answer 36

MCIR gene

Question 37

Often referred to "age spots" or "liver spots", what are they?

Answer 37

Actinic Lentigines

Question 38

What is Actinic Lentingines?

Answer 38

"Age spots" related to UV exposure -Increased number of melanocytes along the basement membrane but without the formation of nests that occur in melanocytic naevi

Question 39

How does Seborrheoic Keratosis arise?

Answer 39

Benign proliferation of epidermal keratinocytes

Question 40

What do Seborrheoic Keratosis commonly look like and where do they appear?

Answer 40

- Very common in ageing skin, found on face and trunk | - Warty, 'stuck on' appearance with a greasy hyperkeratotic surface with a visible pinpoint keratin plug

Question 41

Are Melanocytic naevi most commonly congential or acquired?

Answer 41

Acquired before the age of 25

Question 42

What is melanocytic naevi?

Answer 42

Localised, benign clonal proliferations of melanocytes

Question 43

What is the % of babies typically born with melanocytic naevi?

Answer 43

1%

Question 44

What are the 3 types of acquired naevi and in what stage of life do they develop?

Answer 44

1) Junctional naevus in childhood 2) Compound naeves in adolescence/ early adulthood 3) Intradermal naevus in adulthood

Question 45

Describe where Junctional, compound and Intradermal Naevi are found

Answer 45

Junctional: clusters of melanocytes found at the DEJ Compound: clusters of melanocytes found at the DEJ and in dermis Intradermal: clusters of melanocytes found entirely in the dermis

Question 46

How does the difference in appearance vary between the junctional, compound and intradermal naevi and how do these differences arise?

Answer 46

Junctional: macular, circular or oval mid-dark brown appearance Compound and Intradermal: both seen as nodules due to dermal content. Intradermal is less pigmented than compound.

Question 47

What are the 2 clinical settings of dysplastic naevi?

Answer 47

- Sporadic: not inherited | - Familial: strong FHx of melanoma, autosomal inheritance, high lifetime risk of developing melanoma

Question 48

Give some examples of rarer naevi

Answer 48

Blue naevi, Halo naevi, Spitz naevi

Question 49

How does a congenital naevus differ from an acquired naevus in how it looks?

Answer 49

Congenital: larger, slightly raised, becomes more rugose and elevated as the child grows older