Module 2: Chaos and Clues Flashcards
Excluding seborrheic keratosis
Multiple orange or yellow clods Multiple white clods Thick curved lines Well demarcated border Multiple grouped similar lesions If in doubt bx
Which clue is most sensitive for melanoma on face
Grey color
Which clue is most specific for melanoma on face
Dot vessels
then grey circles
then pigmented circles
Exceptions to decision algorithm
changing lesions in adults
nodular or small lesions with any clue
Head/neck pigmented circles or dermatoscopic grey
Acral parallel ridge patterns (can be symmetrical)
Polarizing specific white lines
BCC
Melanoma
Spitz nevus
Dermatofibroma
Where to look for dot vessels in melanoma?
Flat sections
Do you get dot vessels in BCC?
Few, but not a pattern.
Do you get serpentine vessels in SCC?
No
What is significance of looped vessels?
Raised lesion = invasive
List vessel structures
Dot, Clod
Line, Looped
Curved, Sepentine
Helical, Coiled
List vessel patterns
Random, Clustered
Serpiginous, linear,
Central, Radial
Reticular, Branched
Priority pigment vs vessel
Pigment takes priority over vessel
Nail matrix melanoma
Lines of varying width interval and color
GET BLACK LOLLIPOPS - most to least sensitive
Grey or blue structures
Eccentric structureless areas
Thick lines reticular
Black dots or clods peripheral
Lines radial OR pseudopods, segmental
Lines white
Lines parallel ridges
Polymorphous vessels
Polygons
Tyndall effect
Air particles scatter light which becomes visible to observer.
Short wavelength light (blue) is scattered 16x more than long wavelength light (red). Sky therefore appears blue.
Chaos and clues has been designed to
assess all pigmented lesions
detects any type malignancy
no need to decide if melanocytic
applied at exam speed
C+Clues Algorithm
Chaos, look for 1 of 9 clues.
If 1 of 9 clues biopsy unless can make unequivocal diagnosis.
Exception - consider bx anyway
RPA
Pattern + colours + clue = diagnosis
5 basic structures
line pseudopod circle clod dot
5 type of lines
reticular branched parallel radial curved
Define line
2 dimensional continuous object L»_space;W
Define Pseudop
line + bulbous end
Define circle
curved lines sensible equidistant from central point
Define clod
well circumscribed solid object > dot. Any shape and colour.