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
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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
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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
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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
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Lentiginous Melanoma
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Lentiginous Melanoma
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Lentiginous Melanoma
What is the controversey around Lentiginous Melanomas?
Compared with lentiginous melanoma, lentiginous naevus is less atypical and asymmetrical in structure, and does not include polygons or grey structures. Some clinicians and pathologists believe Lentiginous Melanomas are just on a spectrum of atypia, and these lesions often have marked asymmetry of structure on dermatoscopy.
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Lentiginous Naevus
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Lentiginous Naevus
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Lentiginous Naevus
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Lentiginous Naevus
What is a ‘nested Melanoma of the elderley’?
This is an evolved lentiginous melanoma/superficial spreading melanoma which has large intraepidermal nests of tumour cells. These result in a globular pattern. The globules are varied in shape, colour and distribution within the lesion.
What is the name for lentinginous melanoma on the palm, sole or underneath the nail?
Acral Melanoma
Describe the Dermatological characteristics of Acral Melanoma
Broad parallel ridge pattern (rather than benign parallel furrow pattern). The asymmetry and other features of superficial melanoma may be present.
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Acral Melanoma-characterised by irregular structure.
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Acral Melanoma-characterised by irregular structure.
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Acral Melanoma-characterised by broad paralell ridge pattern (not benign furrow pattern) with irregular structure.
NB: Little white dots on the ridges are sweat ducts (acrosyringia) and confirm palmoplantar location. In melanoma, these dots disappear because the acrosyringia are destroyed by the malignant process.
Name this picture. What is it a type of? What are the characteristics of an early lesion, and describe a positive Hutchinson’s sign.
Subungual Melanoma, a type of Acral Melanoma.
Characteristics of an early lesion include widening pigmented bands, irregular in spacing and varying colour (including pink or red in amelanotic melanoma).
A positive Hutchinson’s sign refers to pigment arising on the skin adjacent to the nail, which is rare in benign naevi.
Name this picture. What is it a type of? What are the characteristics of an early lesion, and describe a positive Hutchinson’s sign.
Subungual Melanoma, a type of Acral Melanoma.
Characteristics of an early lesion include widening pigmented bands, irregular in spacing and varying colour (including pink or red in amelanotic melanoma).
A positive Hutchinson’s sign refers to pigment arising on the skin adjacent to the nail, which is rare in benign naevi.
Name this picture. What is it a type of? What are the characteristics of an early lesion, and describe a positive Hutchinson’s sign.
Subungual Melanoma, a type of Acral Melanoma.
Characteristics of an early lesion include widening pigmented bands, irregular in spacing and varying colour (including pink or red in amelanotic melanoma).
A positive Hutchinson’s sign refers to pigment arising on the skin adjacent to the nail, which is rare in benign naevi.
Why is nodular melanoma often difficult to identify clinically and dermatoscopically?
Melanoma features can be noted on the periphery of the lesion and this can be missed. The lesion may composed of only two or three colours and these may be distributed fairly symmetrically. Sixty percent of nodular melanoma is amelanotic.
What are some possible features of nodular melanoma, and what other lesions can it resemble?
Isolated globules
Blue-grey veil
White streaks
Irregular linear or dotted vessels
Nodular Melanoma may resemble seborrhoeic keratosis, basal cell carcinoma or angioma.
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Nodular Melanoma with regular shape
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Nodular Melanoma with irregular shape/structure
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Nodular Melanoma with irregular shape/structure
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Nodular Melanoma with irregular structure
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Nodular Melanoma with irregular structure
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Nodular Melanoma with irregular structure
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Nodular Melanoma with irregular structure
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Nodular Melanoma with irregular structure
What are some dermatological characteristics of Amelanotic melanoma?
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
NB: Too much pressure by dermoscope instrument may obscure the vascular pattern.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma (dermoscopy)
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma (dermoscopy)
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma (dermoscopy)
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture? What are some characteristics in general for these lesions?
Amelanotic Melanoma
- History of change within an atypical pink lesion.
- Small focal and irregular pigmentation, often on the periphery.
- Atypical vascularity: linear, dotted, corkscrew or polymorphous vessels.
Name this picture
What are some general dermatoscopic features of this lesion type?
What does it appear clinically similar to?
Desmoplastic Melanoma
Dermoscopic features may include-Atypical vascular structures, grey dots, or other melanoma-specific structures. If associated with lentigo maligna, features of lentigo maligna may coexist.
Appears clinically similar to Dermatofibroma
In the ‘Chaos and Clues’ method of identifying Melanoma, CHAOS is definded by asymmetry of structure and/or colour, and at least one clue to diagnose malignancy, what are the 9 clues?
1-Thick reticular lines
2-Grey or blue structures of any kind
3-Pseudopods or radial lines at the periphery
4-Black dots in the periphery
5-Eccentric structureless area of any colour
6-Polymorphous vascular pattern
7-White lines
8-Parallel lines on ridges
9-Large polygons.
