ORIGINAL RESEARCH
Dermoscopic ‘Chaos and Clues’ in the diagnosis of
melanoma in situ
Rajan Ramji,
1
Guillermo Valdes-Gonzalez,
2
Amanda Oakley
1,3
and Marius Rademaker
1,3
1
Waikato Clinical Campus, University of Auckland, Hamilton, New Zealand,
2
Dermatology, Medicina
Guadalajara Medical Center, Guadalajara, Mexico, and
3
Waikato Hospital, Hamilton, New Zealand
ABSTRACT
Background/Objective: To describe the dermo-
scopic features of melanoma in situ using the Chaos
and Clues method.
Method: Histologically proven primary melanoma
in situ (MIS) diagnosed through a specialist teleder-
moscopy clinic were reviewed by three dermatolo-
gists. By consensus they agreed on the global
dermoscopic pattern, colours, presence of chaos
(asymmetry of colour and structure and more than
one pattern), and each of the nine clues described
for malignancy.
Results: One hundred MIS in 92 patients of Euro-
pean ethnicity (45 males) were assessed. Mean age
was 67.3 years (range 20–95). The mean dimensions
of the lesions were 11.1 9 12.0 mm (range 2.5–
31.3 9 2.3–32.3 mm). Using pattern analysis, 82% of
the lesions had three or more patterns (multicompo-
nent) and the rest had 2 patterns. Colours included
light brown (100%), dark brown (98%) and grey
(75%). All MIS demonstrated chaos. The most preva-
lent clues were thick lines (88%), eccentric struc-
tureless areas (88%), and grey or blue structures
(75%).
Conclusion: Dermoscopy can be very helpful in
the early diagnosis of melanoma and MIS. The
Chaos and Clues method is simple to use. Its unam-
biguous descriptors can be successfully used to
describe MIS. The presence of chaos and clues to
malignancy (including thick lines, eccentric struc-
tureless areas, and blue/grey structures) should
raise a red flag and lead to referral or excision.
Key words: chaos and clues, dermatoscopy, der-
moscopy, melanoma in situ, pattern analysis.
WHAT THIS RESEARCH ADDS
• Chaos and Clues is a dermoscopic algorithm using
revised pattern analysis to identify skin lesions sus-
picious of malignancy.
• Most MIS will display both chaos and clues. Clues
can be subtle in some lesions, due to sparse pig-
mentation or an early stage of development.
INTRODUCTION
Chaos and Clues is a dermoscopic pattern recognition
method based on simple geometric elements and patterns.
1
Chaos is defined as ‘asymmetry of structure or colour’,
with the shape of the lesion not being relevant.
1
If chaos is
present, the search for at least one clue is undertaken to
determine the risk of malignancy.
The Chaos and Clues method is simple to use yet is as
effective as other methods in diagnosing skin cancer with
a sensitivity of 90.6% and specificity of 62.7%.
1–3
To date
there have been few reports of using the Chaos and Clues
method to identify melanoma in situ (MIS).
3,4
The aim of
the present study is to describe the dermoscopic features
of MIS, with a secondary objective to determine if any
characteristic of the patient or lesion is predictive for any
specific dermoscopic feature.
MATERIAL AND METHODS
This was a retrospective study of a sample of melanomas
in situ diagnosed from 2010 to 2016 through the virtual
lesion clinics (VLC) or teledermoscopy services of the Wai-
kato and Waitemata District Health Boards, New Zealand.
5
The database included demographic and skin cancer his-
tory for all patients. Only lesions confirmed histologically
Correspondence: Dr Amanda Oakley, Department of Dermatol-
ogy, Waikato Hospital, Private Bag 3200, Hamilton 3140, New
Zealand. Email: Amanda.oakley@waikatodhb.health.nz
Rajan Ramji, BSc. Guillermo Valdes-Gonzalez, MD. Amanda
Oakley, FRACP. Marius Rademaker, DM.
Submitted 7 July 2017; accepted 19 August 2017.
Australasian Journal of Dermatology (2017) , – doi: 10.1111/ajd.12740
© 2017 The Australasian College of Dermatologists