Skin Cancers

Question 1

Do basal cell carcinomas metastasise?

Answer 1

Very rare for these to metastasise but slowly cause local destruction if left untreated however, can be locally aggressive. Also known as rodent ulcers.

Question 2

What are the risk factors for basal cell carcinomas?

Answer 2

Sun exposure – sporadic exposure with episodes of burning most important
X-ray exposure
Immunosuppression
Arsenic exposure

Question 3

How do the two main types of basal cell carcinomas appear?

Answer 3

Nodular
Pearly white nodule
Rolled telangiectatic edge
Usually on the face or sun-exposed sites
May have a central ulcer
Metastasis very rare but slowly causes local destruction

Superficial
Red scaly plaques
Raised smooth edges
Often found on the trunk or shoulders

Question 4

How are basal cell carcinomas managed?

Answer 4

High risk lesion on the head and neck should be referred urgently via 2WW in case SCC
Surgical removal or curettage (effectively scrapes lesion off the skin)
Cryotherapy
Topical fluorouracil or imiquimod for superficial at low risk sites
Radiotherapy
Photodynamic therapy

Question 5

What are squamous cell carcinomas easily confused with?

Answer 5

Can be confused with a keratoacanthoma – a fast growing benign self-limiting papule plugged with keratin.

Question 6

What are the risk factors for squamous cell carcinoma?

Answer 6

Cumulative sun exposure has a direct correlation
Immunosuppression commonly from renal transplant or HIV
Fair Skin
Human papillomavirus
Male
Smoking
Genetics – xeroderma pigmentosum and oculocutaneous albinism

Question 7

What do squamous cell carcinomas present as?

Answer 7

Usually presents as a persistently ulcerated or crusted firm lesion
Erythematous keratotic papules or nodule
Hard raised edges in sun exposed sites
May begin as solar keratoses
Found on lips of smokers or in long standing ulcers (Marjolin’s ulcers)
Tender or itchy non-healing wound

Local destruction can be extensive and may metastasize

Question 8

How are squamous cell carcinomas managed?

Answer 8

Excision with 4mm margins if lesions <2cm, if lesions >2cm then 6mm margins

Mohs micrographic surgery may be used in high-risk patients and in cosmetically important sites.

Radio or chemotherapy if metastasis

Question 9

What are solar (acitinic) keratoses?

Answer 9

Appear on sun exposed skin as crumbly yellow-white crusts, can also be pink, red, brown or same colour as skin. This is from dysplastic intra-epidermal proliferation of atypical keratinocytes. Typically seen on sun exposed areas of skin. Can show a malignant change to SCC over several years about 0.1%.

Question 10

How are solar keratoses managed?

Answer 10

No treatment or emollient
Diclofenac gel used twice daily
5% topical fluorouracil – once or twice daily for up to 6 weeks
5% Imiquimod cream – 3x weekly for 4 weeks and then reassess
Cryotherapy
Photodynamic therapy – not widely available but useful for areas that are difficult to heal
Surgical excision if resistant to treatment or suspecting SCC

The last 3 cause an inflammatory reaction resulting in necrosis and epithelialization.

Question 11

What is bowen’s disease?

Answer 11

This is SCC in situ with a well-defined slow growing red/brown scaly plaque on lower legs. Full thickness dysplasia is seen on histology. Infrequently progresses to SCC – 3-5%. Occurs as a result of sun exposure, radiation, immunosuppression and arsenic.

Question 12

How should bowen’s disease be managed?

Answer 12

Treatment with cryotherapy, topical fluorouracil, photodynamic therapy or excision.

Question 13

Does melanoma always occur from a melanocytic naevi?

Answer 13

Usually a de novo growth rather than in a previous melanocytic naevi.

Question 14

What are the risk factors for melanoma?

Answer 14

Older age
UV exposure (short periods of intense UV especially at a young age), sun burn
Family History of Melanoma
Personal history of any skin caner
High freckle density or melanocytic or dysplastic naevi
Red or blond hair colour and fair complexion
Slightly more common in women

Question 15

What are the clinical features of a melanoma?

Answer 15

Craggy, poorly demarcated and irregular black lesion

Question 16

Describe the ABCDEF criteria for melanomas

Answer 16

ABCDE criteria for Melanoma
Asymmetry
Border irregularity or blurring
Colour variation with non-uniform shades of black, brown, blue or pink
Diameter >6mm (cannot be covered by the end of a pencil)
Evolution – changes in elevation, size or colour
Funny looking – stands out from the rest

Question 17

Describe the Glasgow 7 point checklist for detecting melanomas

Answer 17

Glasgow 7-point checklist (refer if 3 or more)

Major (2 points)
Change in size
Change in shape
Change in Colour

Minor (1 point)
Inflammation 
Sensory change 
Diameter >7mm unless growth in vertical plane
Crusting or bleeding

Question 18

Describe the 4 types of melanoma?

Answer 18

• Superficial spreading melanomas (70%) – grow slowly, metastasise late, and have a better prognosis overall. Young people.
• Nodular melanomas (15%) – Invade deep, and metastasis early. Note nodular may sometimes be amelanotic and appear red. Often bleeds or oozes. Middle aged people.
• Lentigo Maligna melanoma arise within a Lentigo Maligna, which are melanomas in situ usually in chronically sun exposed skin in older people
• Acral Lentiginous (rare) – nail, palms, soles and most common in African American or Asians. Appears as subungual pigmentation. If from nailbed to nailfold then Hutchinson’s sign.

Question 19

How are melanomas managed?

Answer 19

Whether the tumour has invaded the basement membrane is a key diagnostic indicator
Urgent excision biopsy with a 2mm margin of normal skin – can be curative
This allows for measurement of tumour depth (Breslow’s thickness) which is a key diagnostic indicator. If Malignant melanoma is confirmed from the biopsy then a wider excision margin and potentially sentinel lymph node biopsy if indicated.

Question 20

How is metastatic melanoma managed after surgery?

Answer 20

Adjuvant therapy
Interferon alpha (IFN-alpha) used to minimise relapse risk in stage 3 disease
Stage 4 has no curative treatment and is palliative
Ipilimumab – antibody against CTLA-4 improves survival in metastatic disease

Question 21

What Breslow thicken corresponds to which excision margin in melanoma removal?

Answer 21

Margin of Excision related to Breslow thickness 
Lesions 0-1mm thick = 1cm excision 
Lesions 1-2mm thick = 1-2cm excision 
Lesions 2-4mm thick = 2-3cm excision 
Lesions > 4mm thick = 3cm excision