Malignant Melanoma Flashcards
Melanoma is a malignant neoplasm of what cell?
Melanocytes
Melanocytes are mainly stimulated by what 2 hormones?
MSH (melanocyte stimulating hormone)
ACTH (Adrenoorticotropic hormone)
ACTH and MSH have the same pre-cursor (so think of it like cross-reactivity)
Does UVA or UVB exposure cause more melanocyte activation?
Which has a greater risk of developing melanoma?
UVA penetrates deeper (greater wavelength) and stimulates melanin production
Fun fact: When sitting in the car only UVA crosses the glass
UVB is more superficial causing sunburns and DNA damage
Melanoma is responsible for 80% of skin cancer deaths despite being the 3rd most common skin cancer. What are the RF for Malignant Melanoma?
The following can be used for any skin cancer or lesion especially when taking a history
When assessing any lesion in an exam setting or when taking a history, what are the 5 prognostic parameters of any new lesion?
When performing an examination of a skin lesion what scoring system is used to determine if the patient should be referred?
Glascow System: >3 = Refer
2 pts: BCE
Irregular Boreders
Multiple Colours
Evolution in Size
1 pt: D+others
Diameter >6/7+
Inflammation
Oozing/Bleeding/Crusting
Pruritic/Altered sensation
When going about a history involving any skin lesion, what must you ask or elicit?
What are the 4 most common pathological subtypes of melanoma?
As these will be part of your differentials, mention something about them that will help differentiate it from others (for 5/5)
1) Superficial Spreading Melanoma
(Slow growth, caucasian)
2) Nodular melanoma
(Raised, ulcerate, bleed)
3) Acral Lentiginous Melanoma
(Dark-skin, palms/soles/subungal)
4) Lentigo Maligna
(Face of Elderly, least aggressive, presents years before aggressive form))
What are your differentials for Melanoma (or any skin lesion)
+ Melanoma
How would you stage a melanoma? Go through it
Breslow Thickness = depth of tumours)
I - <1mm (95-100%)
II - 1-2mm (80-95%)
III - 2-4mm (60-75%)
IV - >4mm (50%)
You want to stage a melanoma for Breslow Thickness.
What is the name of the procedure used to provide a sample to assess for Breslow Thickness?
How is the “Thickness measures”
Excisional Biopsy and not Wide local excision
Breslow thickness is the depth of the tumour measured from the level of the epidermis to the maximum depth of tumour
i.e. if nodular, we do not measure from the tip but from the skin (epidermis)
What is the most important prognostic factor for melanoma?
Breslow thickness or just depth of tumour from epidermis
When is sentinel node biopsy indicated for melanoma?
Is it performed as part of diagnosis to assess the extent of the spread or is it performed intra-operatively such as in breast cancer?
Indicated when Breslow thickness >0.8mm (0.8+)
It is performed “intra-operatively”
When is assessing for metastasis indicated for melanoma?
What investigations would you perform?
Breslow Thickness >1mm (1mm+)
PET CT FDG
MRI brain
How is an excisional biopsy performed (parameters)
Excisional biopsy is performed by excising the tumour with
2-3mm margin + 1 layer
e.g. if limited to skin => cup of fat
What are the diagnostic and staging investigations for malignant melanoma?
Diagnosis:
0) Clinical
1) Excisional biopsy with 2-3mm margins and cup of fat for Breslow thickness
2) Dermoscopy (rarely used)
3) PET CT FDG
4) MRI brain (one of the most common)
What is Dermoscopy and when is it used?
Non-invasive microscopy looking at the edges and patterns of skin lesions but only really used for clarifying a diagnosis if still unclear without needing to perform an excisional biopsy
What genetic mutations are associated with melanoma? (top 3 in order)
S-100
BRAF
PDL-1
KRAS
Give me 2 Anti-PDL1 medications. What are these called?
give me 1 BRAF inhibitor
Checkpoint inhibitors -
Pembrilizumab
Nivolumab
Dabrafenib (other is vemurafenib)
What is the curative surgery used in malignant melanoma?
Wide local excision
Only performed after confirmation of malignancy
If an excisional biopsy takes the lesion out with 2-3mm margins, what does the wide local excision include then?
It is the “definitive treatment” whereby larger margins are taken based on Breslow thickness, tumour type, and staging.
When is radiotherapy indicated for treatment of melanoma?
Is it adjuvant or neoadjuvant?
Adjuvant radiotherapy is given to
1) Head and neck LN metastasis
2) Palliative care
What is your approach to reconstruction after wide local excision of a melanoma?
It is based on the size and depth of the defect, location of the melanoma, tension of the wound, and cosmetic and functional considerations
1) Primary closure (when feasible)
2) Skin graft, split thickness if only epidermis removed or full thickness if down to dermis
3) Local Flaps (for functionally or cosmetically important areas such as face, nose, lips, and ears)
4) Regional or free flaps (rare)
If there is recurrence in the same site, how would you manage that. (3 techniques)
1) Re-excision
2) CO2 laser (for small lesions)
3) Isolated Chemotherpeutic limb perfusion
What is isolated chenmotherapeutic limb perfusion and when is it used?
What chemotherapy agent is used?
It is a high dose regional chemotherapy technique that is confined to a single limb
(this is done by applying tourniquet to proximally and cannulating the major vessel of the limb and connecting it to a cardiopulmonary bypass machine, all at hyperthermic temperatures (39-41C) to improve drug penetration - crazy shit)
It is performed for recurrence, locally advanced tumours or unresectable ones. (used also to avoid limb amputations in these patients)
Malphalan is used
