Dermoscopy of Melanoma Flashcards
What does Melanoma most commonly arise from, and where else can it arise?
Melanoma most commonly arises from Melanocytes, however can also arise from Mucosal surfaces, under the nails and in the meninges.
From what naevi or other skin lesions can Melanoma arise?
Melanoma may arise from Atypical (dysplastic) Melanocytic naevi, common acquired Naevi, solar lentigo or atypical lentigo. However, they most arise de novo (without precursor).
Name 11 possible features of superficial melanoma under Dermoscopy
Blue-white veil
Multiple brown dots
Pseudopods
1-Radial streaming
2-Scar-like depigmentation
3-Peripheral black dots/globules
4-Multiple (5-6) colours, especially red and blue
5-Broad network
6-Focal sharply cut-off border
7-Negative network
8-Irregular vascularity
Describe the ‘blue-white veil’, and what is it due to?
The blue-white veil is described as an irregular structureless area of confluent blue pigment with a ground glass haze, as if the image were out of focus. It is due to hyperkeratinisation over dense epidermal pigment. In melanoma they are focal, asymmetrical and irregular.
What is the important prognostic factor in Melanoma and how is it measured?
Breslow Thickness:
AKA Breslow depth, is the thickness of an invasive melanoma in millimetres measured from the granular cell layer to the deepest tumour cell. Breslow thickness is an important prognostic factor so should be measured and recorded on the histology report.
What is Lentigo Maligna and what are the 3 primary dermatoscopic characteristics?
Lentigo maligna is a special type of melanoma in situ arising on sun damaged sites.
1-Thick pigmented lines around appendageal openings, sometimes called rhomboidal structures
2-Asymmetric pigmented follicular openings
3-Slate grey dots and globules
Name this picture
Lentigo Maligna
Name this picture
Lentigo Maligna
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Lentigo Maligna
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Lentigo Maligna
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Lentigo Maligna
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Lentigo Maligna
Name this picture and it’s most obvious patterns?
Lentigo Maligna with annular granular pattern and rhomboids.
Name this picture and one of it’s most obvious patterns?
Lentigo Maligna with annular granular pattern.
What is Lentigo Maligna Melanoma?
Lentigo maligna melanoma (invasive melanoma arising in lentigo maligna) shows the features of lentigo maligna in its in situ component, as well as features typical of invasive melanoma.
Name the picture, what makes you think this?
Lentigo Maligna Melanoma. Irregular shape/structure
Name the picture, what makes you think this?
Lentigo Maligna Melanoma. Irregular shape/structure
Name the picture, describe this lesion.
Superficial Spreading Melanoma (SSM)-Facial
It is a form of melanoma where malignant cells tend to stay within the tissue of origin (epidermis), in an ‘in-situ’ phase for a prolonged period (months to decades). At first, superficial spreading melanoma grows horizontally on the skin surface – this is known as the radial growth phase. The lesion presents as a slowly-enlarging flat area of discoloured skin.
Name the picture, describe this lesion.
Superficial Spreading Melanoma (SSM)-Facial
It is a form of melanoma where malignant cells tend to stay within the tissue of origin (epidermis), in an ‘in-situ’ phase for a prolonged period (months to decades). At first, superficial spreading melanoma grows horizontally on the skin surface – this is known as the radial growth phase. The lesion presents as a slowly-enlarging flat area of discoloured skin.
Name the picture, what makes you think this?
Lentigo Maligna Melanoma. Irregular shape/structure
What is lentiginous melanoma?
a) Where does it most commonly arise and in what age?
b) Name the most common dermatoscopic features (6)
Lentiginous melanoma is a proliferation of malignant pigment cells (melanocytes) along the basal layer of the epidermis. The precursor lesion is an atypical solar lentigo or a lentiginous / junctional naevus. It arises on the trunk and priximal limbs, most commonly in the middle-age range of 40-80yo.
Most common Features include:
1-Irregular shape, structure and colour
2-Grey or brown lines forming polygons (larger than perifollicular rhomboid structures of lentigo maligna)
3-Grey dots
4-Multiple hypopigmented areas
5-Structureless areas
6-Fine pigment network or fingerprinting
Name this lesion?
Lentiginous Melanoma
Name this lesion?
Lentiginous Melanoma