1. Cutaneous Malignancies
MBChB IV

2. Outcomes for this lecture
After this lecture the student should be able to:
Name the 5 most common skin malignancies
Discuss the aetiology of skin cancer
Recognise and describe the clinical presentations of the different types of basal cell carcinoma, squamous cell carcinoma, solar keratosis, melanoma and keratoacanthoma
Name the risk factors for the development of melanoma
Explain the nature and implications of dysplastic nevi
Name the danger signs that may be present in pigmented lesions that can point to the diagnosis of melanoma (ABCDE)
Describe in detail the procedure that has to be followed to confirm the diagnosis of a suspicious looking pigmented lesion
Broadly discuss the management of the different types of skin cancer

3. Most Common Forms of Skin Cancer
Basal cell carcinoma
Solar keratosis
Squamous cell carcinoma
Melanoma
Keratoacanthoma (?)
Many others

4. Etiology of Skin Cancer
Ultraviolet light – UVB: Squamous cell CA
Basal cell CA
– UVA: Melanoma
Genetic – predisposition (Celtic decent)
albinism
syndromes
Human papilloma virus (genital)
Ionic irradiation
Chemicals – Arsenic
Coal tar
Heat

5. Basal Cell Carcinoma Most common infiltrating malignancy in humans
Very slow growth tempo
Different types
Practically never metastasizes
Often multiple
Never on mucous membranes

6. Basal Cell Carcinoma: Types
Nodular
Ulcerative
Superficial spreading
Sclerosing
Pigmented

20. Management: Therapeutic
Curettage and cautery
Surgical excision
Radiotherapy
Intralesional interferon
Topical imiquimod
Always confirm histologically
Never freeze!

21. Management: Advice / Information
Explain prognosis
Sun exposure
Sunscreen creams
Self examination of rest of skin
Education of children

22. Management: Follow-up
6-monthly for 4 years
Scar + rest of skin

23. Solar Keratosis Extremely common
Small squamous carcinoma, limited to the epidermis, not full thickness
Not “pre-malignant”
Pink base, whitish hyperkeratosis on top
No fleshy component palpable

29. Solar Keratosis: Treatment
Cryotherapy
Curettage
5-Fluorouracil ointment
Imiquimod cream
Photodynamic therapy
Seldom surgery necessary

30. Squamous Cell Carcinoma
Second most common infiltrating skin CA
Grows faster than BCC, more aggressive
Low incidence of metastases (lymph nodes)
Common on mucous membranes (smoking)
Majority begin as solar keratoses

40. Management Surgical excision still first choice Radiotherapy
Topical imiquimod only for in-situ lesions
Lymph node dissection for metastases
Never freeze

41. Melanoma Most malignant tumour in humans Very common (epidemic)
Caused by high exposure to UVA in childhood
?Role of sunscreen creams
Familial predisposition (genetic defects)
Metastasizes early, rapidly

42. Melanoma: Risk Factors
More than 30 melanocytic nevi
Three or more dysplastic nevi
Light skin that sunburns easily
Three or more severe sunburn episodes as a child
Family history of melanoma
Previous melanoma
Exposure to sunbed tanning

43. Melanoma: Risk Factors
NB: Dysplastic nevi and common melanocytic nevi seldom (if ever) precursors of melanoma

44. Melanoma: Clinical Appearance
A: Asymmetry
B: Border – irregular
C: Colours – different shades of brown and black
D: Diameter – > 6mm
E: Evolution – changes in appearance

45. Melanoma: Types Superficial spreading Nodular Acral lentiginous
Lentigo maligna
Other (e.g. amelanotic)

61. Melanoma: Diagnosis Clinically: Changing pigmented lesion
Biopsy: Conservative excision of whole lesion with 1mm edge of normal tissue
If lesion too big: Incision biopsy of thickest / blackest part, including edge
Never punch biopsy
Never primary wide excision based on a clinical diagnosis!!!

62. Melanoma: Treatment
Wide surgical excision according to Breslow thickness of tumour
Sentinel lymph node dissection for tumours between 1mm and 4mm thick
Therapeutic lymph node dissection if positive

63. Melanoma: Investigations
Exclude metastases
Examine the rest of the skin!!

64. Melanoma: Follow-up 6-Monthly, life long
Look for recurrence, metastases, new lesions

65. Patients With Many Moles
Follow up photographically
Dermatoscopy
Prophylactic excision of moles not indicated