Malignant Melanoma Flashcards
Define malignant melanoma
Abnormal pigment-producing cells grow uncontrollably and can spread to other body parts
What genetic mutations are commonly associated with melanoma?
- 60% of melanomas have a BRAF mutation.
- Acral melanomas may have c-kit mutations
What is the most common type of malignant melanoma?
Superficial spreading melanoma (SSM)
Define Superficial spreading melanoma (SSM)
- Flat
- Irregularly pigmented lesion
- Often on trunk and limbs
What characterises acral lentiginous melanoma?
Pigmented lesions on palms, soles, or under nails, presenting late
Where does lentigo maligna melanoma typically occur?
Sun-damaged skin of the face, neck, and scalp
What is the most aggressive type of melanoma?
Nodular melanoma
= Rapidly growing, pigmented nodule that may bleed or ulcerate
What is the difference between radial and vertical growth phases of melanoma?
Radial growth phase (RGP)
= Horizontal growth, often in situ.
Vertical growth phase (VGP)
= Dermal invasion, capable of metastasising
Why is nodular melanoma more aggressive?
It lacks the radial growth phase and begins directly in the vertical growth phase
What are signs that a lesion might be melanoma?
- Change in shape
- Irregular pigmentation
- Bleeding
- Ulceration
- Satellite nodules
What is the ABCDE checklist for melanoma?
Asymmetry
Border irregularity
Color variation
Diameter >6mm
Evolves over time
What does Breslow thickness measure?
The depth of the tumor from the granular layer of the epidermis
(part of the skin’s outer layer (epidermis))
What is the significance of Breslow thickness?
The greater the Breslow thickness, the worse the prognosis
What tests are done if metastasis is suspected in melanoma?
PET scan or CT scan
What is the first step in managing melanoma?
Narrow excision for diagnosis and to assess Breslow depth
What is the standard excision margin for melanoma?
1 cm of normal skin around the lesion for every 1 mm of Breslow depth
What treatments are available for advanced melanoma?
Chemotherapy, immunotherapy, and genetic therapies
What are common genetic therapies used in melanoma?
- Imatinib for c-kit mutations
- BRAF inhibitors (eg, dabrafenib/vemurafenib) for BRAF mutations
Which cells are malignant melanomas derived from?
Melanocytes
How many grades are there on the Fitzpatrick skin type scale?
6
A 58-year-old man attends the GP as he is concerned about a lesion that he has found on his shoulder a week ago.
On examination, there is a single pigmented lesion on his right shoulder. It is asymmetrical and has a ‘scalloped’ border.
It measures 4mm across and is variegated in colour. A general skin survey reveals no further lesions.
What would be the most appropriate next step in the management of this patient?
Urgent referral
A 45-year-old woman is referred by the GP to a dermatologist with a lesion that she suspects is a melanoma.
Under dermoscopy, the dermatologist finds a 10mm, irregular, asymmetrical pigmented lesion that is variegated in colour. An excisional biopsy is performed and histology confirms the diagnosis of malignant melanoma with a 2mm Breslow thickness.
What is the best next step in the management of this patient?
Sentinel node biopsy
A sentinel node biopsy should be performed to look for evidence of metastases and stage the cancer when the Breslow thickness is greater than what?
1mm
A 35-year-old woman presents to her GP with a circular brown raised lesion which is soon diagnosed as a malignant melanoma.
Which type of malignant melanoma is most commonly found on the legs of young and middle-aged adults?
Superficial spreading melanoma
