11 - Skin Flashcards
What is lentigo maligna?
Associated with chronic sun exposure
What are the risk factors for malignant melanoma?
UV Light (not for acral though)
- Severe blistering sun burn in childhood
- Immunosuppression
- Multiple (>100) or giant (>20 cm) naevi
- Skin type (Fitzpatrick Skin types I & II)
- Family history (cyclin-dependent kinase mutations)
- Genetic mutations (CDK4, xeroderma pigmentosum, melanocortin 1 receptor)
What is the epidemiology of melanoma?
5th most common cancer in UK
1.5X more likely in men, with men on trunk and women on legs
Why is there a worse prognosis with melanoma in non-caucasian patients?
Often diagnosed late due to:
- Poor public awareness
- Lower index of suspicion
- Detection more challenging (often acral)
What is the progression of melanoma starting from a benign navei?
Due to UV light (mostly UVA) causing damage to DNA
- Benign naevus (typical mole)
- Dysplastic naevus (atypical mole)
- Radial growth phase - melanomas tend to extend superficially and outwards initially
- Vertical growth phase - malignant cells invade the basement membrane and proliferate vertically downwards into the dermis.
- Metastasis - usually to lymph nodes
What are the features of malignant melanoma?
ABCDE
USE DERMATOSCOPE
What are the criteria for a 2 week wait referral for a melanoma?
Over 3 points on the 7 point checklist
Major criteria are 2, minor are 1
If dermatoscopy reveals a suspicious mole, what investigation should be done next?
Excisional biopsy with 2mm margin and subcutaneous fat
May have punch biopsy if legion is large or close to vital structures
What are the different subtypes of melanoma from most to least common?
- Superficial spreading (70%)
- Nodular (15%)
- Lentigo maligna (10%)
- Acral lentiginous (<5%)
- Desmoplastic melanoma (<1%)
- Amelanotic
How do the following melanomas grow:
- Superficial spreading
- Nodular
- Lentigo maligna
Superficial Spreading: Initial radial then vertical growth
Nodular: Immediately vertically grow
Lentigo Maligna: long period of intra epithelial growth
What is the histological classification system for melanoma and how does this determine prognosis?
- Breslow thickness: deeper = poor prognosis, from S.Granulosum to epidermis
- Mitotic index
- Ulceration: poor prognosis
- Clark Level I-IV: lost relevance
What is the margin of excision with biopsy for melanoma?
Initial 2mm clear margins in excision biopsy then go back after got Breslow thickness
When should you do a sentinel node biopsy in melanoma?
When Breslow thickness >0.8mm or if <0.8mm with ulceration
After histological diagnosis of melanoma, what are some further investigations done for staging?
- Lymph node exam: fine needle aspiration (FNA) and cytology if any suspicious
- Total body CT or PET-CT: only if high-risk for distant metastasis include those with aggressive lesions (pT4, ulcerated, high mitotic index etc.) or the presence of known lymph node spread
- LDH: useful for risk stratifying
How is melanoma staged?
TNM or AJCC
- Tumour - Breslow thickness (mm) +/- presence of ulceration
- Node - whether melanoma has spread to lymph nodes and how many
- Metastases
How is melanoma managed?
Always guided by MDT
Wide local excision (WLE)
Removal of the biopsy scar with a surrounding margin of ‘healthy’ skin, with fat, down to muscular fascia
Sentinel Lymph Node Biopsy (SLNB)
Typically, on the morning of surgery, a radio-labeled tracer is injected into the old biopsy scar. A CT scan is then performed which identifies ‘hot spots’
A postitive SLNB usally results in referral for lymphadenectomy. This is stage 3
Electrochemotherapy
Patients with locally advanced melanoma
Uses pulses of electricity together with chemotherapy injected into tumour
Adjuvant therapy
If stage 4
- Chemotherapy
- Radiotherapy
- Immunotherapy
How long after WLE of melanoma are patients followed up for?
Depends on staging
•Patient education for all: self-examination, sun protection, avoiding vitamin D depletion
•Discharge if stage 0
•Follow-up for up to 5 years (every 3 months initially), depending on stage
•Personalised follow-up for Stage IV
What are some examples of immunotherapy used in stage ¾ melanoma?
- ipilimumab
- nivolumab
- pembrolizumab
What is some targeted therapy in melanoma and what gene does this target?
BRAF gene mutation
Used for aggressive melanomas
- Vemurafenib
- Dabrafenib
- Trametinib
What determines the prognosis with melanoma?
What is the 5 year survival with melanoma?
How can brain metastases in melanoma be managed?
- Steroids
- Surgical resection
- Stereotactic or whole brain radiotherapy
How may brain metastases present?
- Headache
- Nausea and vomiting
- Fatigue
- Weakness
- Seizures
- Cranial nerve palsies
How is stage 0-II melanoma managed?
How is stage III melanoma managed?
How is stage IV melanoma managed?
What is the commonest type of skin cancer and the risk factors for this?
BCC (from keratinocytes)
- UV light exposure
- Family history
- Fitzpatrick skin types I & II (light skin, tans poorly)
- Male sex
-
Genetics:
- Mutations in PTCH, p53, ras, fos
- Albinism
- Gorlin’s syndrome
- Xeroderma pigmentosum
- Increasing age
- Previous skin cancers
- Immunosuppression (e.g. AIDS / transplantation)
- Carcinogens: Ionizing radiation, arsenic, hydrocarbons
What is Gorlin-Goltz syndrome?
- Genetic condition increases the risk of developing BCCs
- Autosomal dominant mutation to PTCH1 gene so BCCs develop in adolescence
How does a typical nodular BCC present?
TURP
- Telangiectasia
- Ulceration
- Rolled edges
- Pearly edge
What are the different subtypes of BCC (most to least common) and how do they appear differently?
Nodular (60%)
- Often on face
- Flesh-coloured well defined borders with pearly rolled edge, surface telengectasia and central ulceration
Superficial (10%)
- Erythematous plaque usually on trunk
Morphoeic
- Deeply invasive and look like scar
Pigmented
- Often mistook for melanoma
Basosquamous
- BCC with SCC differentiation, high recurrence and metastases
How is a BCC diagnosed?
- Dermatoscopy
- Biopsy unsure
- CT if think invasive
BCC are stratified based on low-risk or high risk and this determines prognosis and management. What are lesions that are classed as high risk meaning they are likely to recur?
Apart from defining a BCC as high risk or low risk, how else can we decide the management plan?
- Performance status of patient
- Co-morbidities
- Use of antiplatelets or anticoagulants
What are the principles of treatment in BCC?
How is high risk BCC managed?
Surgery and radiotherapy
- Standard surgical excision margins: 4-5mm (may increase for morphaeic and larger BCCs)
- Radiotherapy good if pt is unsuitable candidate for surgery (contraindicated if for recurred BCC post RT of previous BCC)
What type of surgery is done in high risk BCCs?
‘Excisional’
- Wide-local excision (common treatment modality) or
- Moh’s Micrographic Surgery (typically reserved for high-risk lesions)
How are low-risk BCCs managed?
- Surgical excision: ‘Destructive’ surgery via curettage +/- cautery or cryotherapy. Only done in low risk as no histology
- For superficial BCC: Topical immunotherapy (5-Fluorouracil or Imiquimoid) or Photodynamic therapy
What margin is used for excision of BCC?
Excised down to subcutaneous fat
- Low-risk (small <2 cm, well-defined): 4-5 mm provides 95% clearance
- High-risk (large >2cm, poorly-defined): 5 mm margin provides 82% clearance; consider referral for Moh’s Surgery
- Recurrent lesions: referral to Skin MDT; re-excision of scar (5-10 mm margins) or Moh’s Surgery +/- Radiotherapy.
Most BCCs do not require follow up. When do BCCs need to be followed up?
- Recurrent
- Multiple BCCs at once
When is Moh’s surgery used for BCC?
What are risk factors for squamous cell carcinoma?
- Excessive exposure to sunlight / psoralen UVA therapy
- Immunosuppression e.g. following renal transplant, HIV
- Smoking
- Long-standing leg ulcers (Marjolin’s ulcer)
- Genetic conditions e.g. xeroderma pigmentosum
- Type I or II skin (fair skin which always burns and never or rarely tans)
- History of frequent or severe previous sun burn
- Personal or family history of skin cancer
- Increasing age
- Male sex
How may SCC present?
Irregular, ill-defined red nodule with scale and ulceration
How is SCC diagnosed?
Biopsy!!!!!!
How do you decide if an SCC is high risk or low risk?
- Site
- Diameter
- Tumour depth and invasion
- Histological features and subtype
- Host immune status
How is SCC treated?
- Surgical excision: usually Moh’s micrographic in high risk
- If local metastases use wide surgical excision radiotherapy
- Sentinel lymph node biopsy and if positive lymphadenopathy
What are the margins for surgical excision of SCC?
- Low-risk tumour (<20mm): 4mm excision margin
- High-risk tumour (>20mm): 6mm excision margin
What are indicators of a good and bad prognosis with SCC?
99% 5 YEAR SURVIVAL
How is SCC followed up?
- Only follow up the high risk SCC for 2-5 years
- Patient education on recurrence of disease e.g self-examination of surgical scar site, local skin and lymph nodes and information sheets
What is Bowen’s disease and what does it look like?
SCC in situ
5-10% chance of turning into SCC
Red scaly patches on sun exposed areas
How is Bowen’s disease managed?
Topical 5-fluorouracil
- BD for 4 weeks
- Often results in significant inflammation/erythema. Topical steroids are often given to control this
Cryotherapy or Excision
What are some differentials for actinic keratoses?
- Bowen’s disease
- Invasive SCC
- Superficial BCC
- Amelanotic melanoa
- Seborrhoeic keratosis
What are the different management options of AK depending on the risk of malignant transformation to SCC?
Conservative: remove risk factors (UV exposure), emollients, sun cream
Medical: Topicals like Fluorouracil 5%, Diclofenac, Imiquimod 5% cream
Surgical: Cryotherapy, PDT
Do AKs need following up?
Only if high risk like organ transplant/immunosuppressed
What is important to ask a patient about their skin when they have a suspicious lesion?
- Any previous lesions like this?
- Any other moles/lesions like this?
- Skin type
What does C mean in ABCDE?
UNIFORMITY of colour
How deep do the following biopsies go?
- Shave
- Punch
- Excision
- Shave: epidermis
- Punch: dermis
- Excision: down to subcut fat
What skin cancer can you not get on the lips?
BCC as arises from hair follicles
What immunotherapy can you use in melanoma and when are they used?
BRAF inhibitors
Used for T3 and above
What is the cause of the different colours in melanoma e.g black, blue, grey, brown?
What are some melanoma mimics?
- Multicomponenet haemangioma
- Intracorneal haemorraghe
- Subungal haematoma
- Benign longitudinal melanonychia
- Pigmented Seborrhoeic keratosis
How can you differentiate between Bowen’s and BCC?
Dermatoscopyy
What is this?
How can you differentiate between a dermatofibroma and a BCC?
Where are the classic locations for a SCC?
What are some SCC mimics?
- Traumatised SK
- Inflammed viral wat
- Large SK
- Giant comedone
- Lymoedema nodule
How are secondary skin cancers referred to secondary care?
How much suncream should you put on and how often?
How do you use 5FU for AKs?
What are the excision margins for skin cancer?