Dermoscopy Certificate Flashcards
Outline the Three Point Checklist
- Asymmetry (asymmetrical distribution of colours/dermoscopic structures)
- Irregular Network (Pigmented network with irregular holes and thick lines)
- Blue/white structures
2/3 –> Positive for melanocytic lesion
Outline the chaos and clues method
pigmented lesion –> chaos present –> clue present –> biopsy. If no chaos –> no biopsy, if no clue no intervention
What are the exceptions to Chaos and Clues “no intervention”?
- Changing lesions on adults
- Nodular/small lesions with any clue
- Head/neck; pigmented circles/dermatoscopical grey
- Acral: parallel ridge pattern
What are the five basic patterns in pattern analysis
Lines Pseudopods Circles Clods Dots
What subtypes of “lines” are there in pattern analysis
Reticular Branched Parallel Radial Curved
In revised pattern analysis, define a LINE
A two dimensional continuous object with length greatly exceeding width
In revised pattern analysis, define a PSEUDOPOD
A line with a bulbous end
In revised pattern analysis, define a CIRCLE
A curved line sensibly equidistant from a central point
In revised pattern analysis, define a CLOD
Any well circumscribed, solid object larger than a dot. Clods may have any shape and any colour.
In revised pattern analysis, define a DOT
An object too small to have a discernible shape
In revised pattern analysis, define STRUCTURELESS
An area with no basic structure predominating
Define CHAOS
Asymmetry of structure or colour (not outline)
How can you remember the clues?
GET BLACK LoLLiPoPs Grey or blue structures Eccentric structureless areas Thick lines reticular Black dots or clods peripheral Lines radial or segmental, pseudopods Lines white Liens parallel ridges (palms/soles) or chaotic (nails) Polymorphous vessels Polygons
What is sebaceous hyperplasia?
Enlarged sebaceous glands typically on the forehead or cheek, usually in a person with oily skin
What are the dermatoscopic features of sebaceous hyperplasia?
Yellow structureless areas in centre.
Radial arranged linear vessels that do NOT cross the centre
Central pore
What rules do you use to avoid missing a melanoma when you think there is a benign lesion on dermoscopy?
- Biopsy lesions with a verrucous surface in the absence of other benign criteria
- Always biopsy regressive lesions (includes lichen planus like keratoses)
- Pyogenic granuloma is a biopsy diagnosis
What mimics pyogenic granuloma?
Amelanotic melanoma
What is lichenoid keratosis?
Also known as lichen planus like keratosis.
Lichenoid keratosis is an inflammatory reaction arising in a regressing existing solar lentigo or seborrhoeic keratosis.
What are the dermoscopic featurs of lichenoid keratosis?
Uniform clusters of grey dots and, depending on the stage of the lesion, may show signs of an original pre-existing lentigo or seborrhoeic keratosis.
What are the dermoscopic features of dermatofibroma?
Central white/lighter patch (compare to surroudnign skin)
Surrounding brown circles
Pigmentation is dependent on skin type- ie in blacker skin; will be darker
What are the three common benign vascular tumours?
Haemangioma
Pyogenic granuloma
Angiokeratoma
What are angiokeratoma?
Haemangioma that induce a keratin surface reaction
What are the dermoscopic features of an angiokeratoma?
Lacunas ( red, black, blue, purple)
Keratotic change on surface
Sometime presence of peripheral erythema
What are the dermoscopic features of pyogenic granuloma?
Bright red with white intersecting lines +/- ulceration
What are the clinical features of a pyogenic granuloma?
Rapidly growing red lesion that frequently bleeds
What is the differential diagnosis for pigmented facial macules?
Lentigo maligna
Pigmented actinic keratosis
Solar lentigo
Lichenoid keratosis
Which non melanocytic skin cancers can be differentiated by dermatoscopy?
Sebaceous hyperplasia Seborrheic keratosis Clear cell acanthoma Bowen's disease Nodular cystic BCC
What non melanocytic skin cancers can NOT be differentiated by dermatoscopy?
Pyogenic granuloma
Uncommon adrenal tumours
Actinic keratosis
