Skin Cancer Flashcards
What are the 3 main types of skin cancer?
Basal cell carcinomas
Squamous cell carcinomas
Malignant melanoma
Describe the effect of UV light on keratinocytes. (2)
- UV light causes DNA damage and mutations (e.g. p53 mutations)
a. This causes abnormal cell proliferation - UV light also causes impaired DNA repair
a. Therefore p53 mutations cannot be corrected before they cause cancer
Describe the effect of UV light on the immune system. (2)
- UV light damages immune system in the skin; causes immunosuppression
- This causes impaired immunosurveillance
a. Therefore cancer cells are not detected/removed, allowing cancer development
What are the 4 subtypes of basal cell carcinoma?
Nodular BCC
Superficial BCC
Pigmented BCC
Morphoeic/sclerotic BCC
Describe the clinical features of a nodular BCC. (5)
Nodule (raised lesion, 0.5+cm) Shiny, "pearly" appearance Telangiectasia Well-defined border Central ulcer
Describe the clinical features of a superficial BCC. (4)
Flat lesion (rough but NOT raised)
Shiny margin (BUT matte centre)
Some telangiectasia
Beginnings of ulceration
Describe the clinical features of a pigmented BCC. (5)
Nodule (raised lesion, 0.5+cm) Shiny, "pearly" appearance Telangiectasia Well-defined border Central ulcer Brown/black discolouration due to melanin
Describe the clinical features of a morphoeic/sclerotic BCC. (4)
Flat lesion
Similar colour to the rest of the skin
Infiltration into surrounding tissue
Shiny, “pearly” appearance
What is the standard method of treating BCC?
What other treatment options exist if this one is not tolerated? (5)
Surgical excision (margins: 5mm)
OTHER OPTIONS: Curretage and cautery Cryotherapy Photodynamic therapy Topical imiquimod/5-fluorouracil Mohs micrographic surgery
List 4 disadvantages of photodynamic therapy.
Very painful
Takes 3-4 hours
Needs to be done at least twice
No margin control
Describe the process of Mohs micrographic surgery. (3)
- Skin is excised piece by piece
- Pathologist is present and tests the skin biopsies as they are taken
a. This continues until a bit of skin is removed that doesn’t have any cancer in it - This results in the smallest area of excision possible
What are the 2 types of pre-malignant change seen before squamous cell carcinoma?
Actinic keratosis
Bowen’s disease
Describe the clinical features of actinic keratosis. (3)
Pre-malignant
Yellow-white scales
Crumbly crust
Describe the clinical features of Bowen’s disease. (3)
Pre-malignant
Red, scaly plaque
Carcinoma in situ
Describe the clinical features of malignant squamous cell carcinoma. (3)
Hyperkeratosis (scaling)
No ulceration
May be raised
What is the standard treatment for malignant SCC? (1)
How would you treat pre-malignant skin lesions? (3)
How would you prevent recurrence of SCC? (2)
MALIGNANT SCC: Surgical resection (margins: 5mm)
PRE-MALIGNANT CONDITIONS:
Topical imiquimod/5FU
Cryotherapy
Photodynamic therapy
PREVENTION OF RECURRENCE:
Always use sun protection
Regular skin checks
What is the risk of metastasis in squamous cell carcinoma?
10-30%
What are the 2 pre-malignant melanoma conditions?
Lentigo maligna
Melanoma in situ
Describe the pathophysiology of malignant melanoma. (4)
- UV light causes DNA damage
- Pre-malignant lesions are formed
- Pre-malignant lesions develop into melanoma, which has 2 growth phases:
a. Radial growth phase - expands laterally
b. Vertical growth phase - expands deeper into skin - Melanoma may metastasise via lymphatics
List the 6 subtypes of malignant melanoma.
Superficial spreading malignant melanoma Nodular melanoma Subungual melanoma Amelanotic melanoma Acral melanoma Lentigo maligna melanoma
Describe the features of a suspicious skin lesion in suspected malignant melanoma. (6)
Irregular colour Irregular shape Change in size/shape/colour Itching Ulceration/bleeding Satellite tumours
Other than a suspicious skin lesion, describe the clinical features of malignant melanoma. (5)
OTHER SKIN FEATURES:
Regressed primary tumour
Lentigines (singular: lentigo)
NAIL CHANGES: Single melanonychia (single band of pigment) Hutchinson's sign (spread of pigment from nails into the skin) Pseudo-Hutchinson's sign (appearance of spread into the skin, though actually only due to a pigmented nailbed visible through translucent skin)
How do you classify malignant melanoma? (2)
Breslow depth (mm; depth of the furthest affected melanocyte)
Clark’s level
What is the standard treatment for malignant melanoma? (1)
What further treatment is needed in high risk melanomas? (3)
Which further assessments would you do? (3)
Surgical excision
- Breslow <1mm: 1cm margin
- Breslow 1+mm: 2cm margin PLUS further treatment
FURTHER TREATMENT: Chemotherapy Vaccine therapy Biologic drugs, e.g. -Bevacizumab -Vemurafenib
FURTHER ASSESSMENT:
Assessment of lymph nodes/metastases
Genetic testing
Long term follow up
List 4 genetic tumour syndromes which might cause skin cancer.
Gorlin’s syndrome
Brook Spiegler syndrome
Gardner syndrome
Cowden’s syndrome
Describe the clinical features of Gorlin’s syndrome. (3)
Multiple BCCs
Jaw cysts
Increased risk of breast cancer
Describe the clinical features of Brook Spiegler syndrome. (2)
Multiple BCCs
Trichoepitheliomas (from hair follicles)
Describe the clinical features of Gardner syndrome. (3)
Soft tissue tumours
Polyps
Bowel cancer
Describe the clinical features of Cowden’s syndrome. (3)
Multiple hamartomas
Thyroid cancer
Breast cancer
