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