Skin cancer Flashcards
BCC
slow growing, locally invasive malignant tumour
BCC risk factors
UV exposure
Immunosuppression
Fitzpatrick type 1
Family history of skin cancer
Xeroderma pigmentosum
Older patients
Previous personal history of skin cancer
BCC genes
PCTH gene
p53 gene
BCC clinical features
Majority occur on sun-exposed areas of the head & neck
Small slow-growing lesions
Raised pearly edges & evident telangiectasia
Rarely cause systemic symptoms
If left to grow → pain, bleeding & ulceration or subsequent invasion into surrounding tissues
BCC types
Nodular (most common) - pink pearly nodule with telangiectasia & can become ulcerated or encrusted
- subtypes = cystic, pigmented or keratotic
Superficial - younger patients
- erythematous scaly plaques with a thread-like border & may bleed + ulcerate
Morphoeic - highest risk of reoccurrence
Basosquamous - mix between BCC + SCC
BCC ddx
Trichoepithelioma
Keratoacanthoma
Cutaneous SCC
BCC ix
Largely clinical diagnosis based on visualisation under dermascope
Can only be confirmed diagnosis through excision biopsy
BCC mx
Depends on the size & where
Small lesion < 2cm, low risk & superficial → surgical excision and topical treatments
Larger lesion > 2cm, high risk, invasive → Moh’s micrographic surgery
Unable to have surgery → radiotherapy
Topical treatments = cryotherapy, photodynamic therapy, immune response modulator, topical chemotherapy, curettage & electrocautery
BCC complications
Recurrence
Local invasion
Metastases (rare) - lymph nodes, bones & lungs
- radiotherapy & palliative treatment
BCC prevention
Reduce exposure to UV light and avoid sunbeds
Frequent use of SPF50 sunscreen & wearing of protective clothing
SCC
Locally invasive malignant tumour of the epidermal keratinocytes which has potential to metastasise
SCC RFs
Smokers
Immunosuppression
Elderly
Chronic skin inflammation
Pre-malignant conditions - Bowen’s disease (irregular scaly plaque usually on sun exposed areas)
Genetic predisposition
SCC clinical features
Highly variable appearance
Can appear nodular, indurated or keratinised with associated ulceration or bleeding
Growth may be over weeks to months
Typically located on sun-exposed sites, eg. hands, forearms, lower limbs & ‘H zone’ of the face
SCC ddx
Other forms of skin cancer
Pre-malignant conditions - bowen’s disease or actinic keratosis
Verrucous carcinoma
SCC types
Cutaneous horn
Keratoacanthoma
Carcinoma cuniculatum
Marjolin ulcer
SCC ix
H&E
Dermoscopy is recommended to aid diagnosis → white circles/structureless areas, looped blood vessels & central keratin plug
Definitive diagnosis = biopsy
Lymph node/metastasis → further imaging +/- fine needle aspiration
SCC classification
Broder’s grade - determined by the ratio of differentiated to undifferentiated cells
SCC mx
Surgical treatment - excision biopsy
Further wide local excision, Mohn micrographic surgery or adjuvant radiotherapy may be offered to patients with one/more involved
Non-surgical treatment - multiple options available
- primary radiotherapy if surgery not feasible
- immune checkpoint inhibitors - locally advanced SCC whether other options not reasonable
- chemotherapy - third line
MM types
Superficial spreading - large, flat & irregularly pigmented lesions, aged 30-50 years
Nodular - rapidly growing, pigmented, bleeding, or ulcerated nodule, typically > 50 years
Lentigo maligna melanoma - large flat pigmented lesions, often in the older population
Acral lentiginous - variable pigmentation, often present with appearance of a stain, typically large size at presentation
MM genes
MAPK pathway - BRAF & NRAS proto-oncogenes
CDKN2A/RB1 pathway - p16 and p14ARF
MM RFs
UV exposure
Age
Previous melanoma
Skin tone - highest in caucasians
Family history
Predisposing conditions - albinism, xeroderma pigmentosum, atypical mole syndrome
Parkinson’s disease !
MM clinical features
New skin lesion or a change in the appearance of a pre-existing mole
May be associated bleeding or itching
ABCDE - asymmetry, border irregularity, colour uneven, diameter > 6mm, evolving lesion
MM ddx
Benign = junctional or compound naevi, intradermal naevi, blue naevi or spitz naevus
Malignant = pigmented basal cell carcinoma, pyogenic granuloma, seborrheic keratosis, kaposi sarcoma
MM ix
Excisional biopsy - confirms diagnosis
MM histological features
Can determine both management or prognosis
Breslow thickness
Degree of ulceration
Histological subtype
Immunohistocytochemistry
Mitotic rate
MM mx
Specialist skin MDT
Ongoing sun protection advice should be given with concurrent vitamin D supplementation & advice on prevention
Wide local excision - indicated in nearly all cases of melanoma
- exact peripheral margin used in wide local excision is guided by the Breslow thickness
Sentinel lymph node biopsy - aims to identify whether or not there is any melanoma in the primary draining lymph node → staging and prognostic procedure only
Metastatic disease - various immunotherapy & chemotherapy agents
MM staging
CT C/A/P & MRI brain
TNM staging → guides treatment and prognosis
