Melanocytic lesions Flashcards
What are the 4 main types of malignant melanoma?
Superficial spreading - (70%)
Nodular - (second most common)
Lentigo maligna - (less common)
Acral lentiginous - (rare)
other rare forms see Passbook
Glasgow 7 point checklist for melanomas.
List the major and minor features
Glasgow 7-point checklist:
Major features:
- Change in size
- Irregular shape
- Irregular colour
Minor features:
- Diameter >7mm
- Inflammation
- Oozing
- Change in sensation
What is the treatment for malignant melanoma?
Suspicious lesions - excision biopsy for diagnosis
Surgical excision
* thin lesions removed using local anaesthetic (normal skin around excised to ensure melanoma cells removed often done as a second procedure after pathology confirmation)
* >1 mm in thickness - wide local excision post initial excision biopsy. Skin graft may be necessary and local lymph nodes tested ( sentinal node biopsy)
Radiotherapy sometimes
Chemotherapy - metastatic
How is the margin of excision to be removed around a malignant melanoma worked out?
Use Breslow thickness of lesion to work out margin of excison
0-1mm thick - 1 cm margin of excision
1-2 mm thick - 1-2 cm (site and pathological features dependant)
2-4mm thick - 2-3 cm (site and pathological features)
> 4 mm thick - 3 cm
What is the Breslow depth?
invasion of the depth of a tumour
What is used to approximate malignant melanoma 5 year survival?
Breslow thickness again!
e.g.
<0.75 mm - 95-100% 5 year survival
0.76 - 1.50 mm - 80-96%
1.51 - 4mm - 60-75%
> 4mm - 50 %
What is a malignant melanoma?
An invasive malignant tumour of the epidermal melanocytes, which has the potential to metastasise
What are risk factors for malignant melanoma?
- sun exposure, particularly during childhood fair skin that burns easily (Fitzpatrick phototypes 1 and 2)
- blistering sunburn
- previous melanoma
- previous non-melanoma skin cancer (basal cell carcinoma, squamous cell carcinoma)
- family history of melanoma, especially if two or more members are affected
- large numbers of moles (especially if there are more than 100)
- abnormal moles (called atypical or dysplastic naevi).
What are you looking for when a pt presents with a suspicious mole that could be a malignant melanoma?
“ABCDE Symptom”s rule
* = major suspicious features
Asymmetrical shape
Border irregularity
Colour irregularity *
Diameter > 6mm
Evolution of lesion (change size/shape) *
Symptoms e..g bleeding / itching
What is this?
Where and who tends to get it?
Related to?
WHAT: Superficial spreading melanoma
WHERE: lower limbs
WHO: young / middle aged adults
RELATED TO: intermittent high intensity UV exposure
What is this?
Where and who tends to get it?
Related to?
WHAT: nodular melanoma
WHERE: trunk
WHO: young and middle aged adults
RELATED TO: intermittent high intensity UV exposure
What is this?
Where and who tends to get it?
Related to?
WHAT: lentigo melanoma
WHERE: face
WHO: elderly pts
RELATED TO: long term, cumulative UV exposure
What is this?
Where and who tends to get it?
Related to?
WHAT: acral lentiginous melanoma
WHERE: common on palms, soles, nail beds
WHO: elderly pts
RELATED TO: no clear relation to UV exposure
What staging system in UK used for malignant melanoma? what factors does it use to stage?
2009 American Joint Committee of Cancer Staging System (AJCC)
Stages I-IV
- primary tumour Breslow thickness
- lymph node involvemnet
- evidence of metastases
What are the ABCD’s of Melanoma?
- Asymmetry
- Border irregularity
- Colour variation
- Diameter over 6 mm
- Evolving (enlarging, changing)
Types of melanomas: Melanomas are described according to their appearance and behaviour. Those that start off as flat patches (i.e. have a horizontal growth phase) include:
- Superficial spreading melanoma (SSM)
- Lentigo maligna melanoma (sun damaged skin of face, scalp and neck)
- Acral lentiginous melanoma (on soles of feet, palms of hands or under the nails – the subungual melanoma)
Types of melanoma: Melanomas are described according to their appearance and behaviour. Melanomas that quickly involve deeper tissues include:
- Nodular melanoma (presenting as a rapidly enlarging lump)
- Mucosal melanoma (arising on lips, eyelids, vulva, penis, anus)
- Desmoplastic melanoma (fibrous tumour with a tendency to grow down nerves)
- Combinations may arise e.g. nodular melanoma arising within a superficial spreading melanoma
What is a melanoma?
- Normal melanocytes are found in the basal layer of the epidermis, i.e. the bottom part of the outer layer of the skin. The melanocytes produce a protein called melanin, which protects the skin by absorbing ultraviolet (UV) radiation.
- Cancerous growth of melanocytes results in melanoma.
What Breslow thickness means a sentinal lymph node biopsy should be carried out? Why?
> 1mm a sentinel node biopsy should be carried out, which can look for evidence of metastases and stage the cancer.
Management based on staging for melanocytic lesions
Based on the stage, a wider excision margin may be taken around the lesion to ensure the cancer has been removed:
Stage 0 = 0.5cm
Stage I = 1cm
Stage II = 2cm
Stage III and IV are metastatic, so adjuvant immunotherapy or chemotherapy is given.
