The impact of GP sub-specialisation and dermatoscopy use on diagnostic accuracy for melanomas in Australia

The impact of GP sub-specialisation and dermatoscopy use on diagnostic accuracy for melanomas in Australia Cliff Rosendahl, Gail Williams, Diann Eley, Tobias Wilson, Greg Canning, Jeffrey Keir, Ian McColl, David Wilkinson. J Am Acad Dermatol10.1016/j.jaad.2011.12.030

How good are we at finding melanomas?

Does it matter?

Photograph by Alan Cameron

NNT Number Needed to Treat for each melanoma diagnosed Number of lesions treated for each melanoma diagnosed Measure of specificity (not sensitivity) Diverse methods of calculation

NNT previous studies Naevi + Melanomas/Melanomas ( 8.7-29.4) Naevi + Melanomas + Seb K/Melanomas (19-30) All lesions EXCISED/Melanomas (39) All predicted Melanomas/Melanomas (4)

Previous NNT studies numbers of melanomas

Previous NNT studies NNT values

Skin Cancer Audit Research Database

Doctor type Dedicated skin cancer practitioner (DSCP) GP with a special interest in skin cancer (GPSISC) General practitioner (GP)

Dermatoscopy use High all pigmented skin lesions Medium most days Low/none less than weekly/not at all

NNT Lesions tested to exclude melanoma / melanomas Prior declaration of intent!

RESULTS

Lesions tested to exclude melanoma (51) (86) (56)

(95% CI P <0.0001) (14.5-20.7) (8.1-9.0) (8.9-10.1) Doctor-type

(95% CI P <0.0001) (12.0-18.6) (9.8-12.4) (8.6-9.3) Dermatoscopy-use

The association between NNT and doctor type remained (P< 0.0001) when adjusted for dermatoscopy use and other variables. The association between NNT and dermatoscopy use disappeared (P = 0.41) when adjusted for practice type and other variables (doctor-type and dermatoscopy use were too inter-dependant)

Fact General practitioners sub-specialized in skin cancer treatment had a higher use of dermatoscopy and excised half the number of benign lesions for each melanoma detected compared to their generalist colleagues Opinion The role of such sub-specialized general practitioners should be defined and the factors that make their performance more effective including trained dermatoscopy use should be promoted

For the first time it is shown that there is a measureable benefit of sub-specialisation in General Practice

Skin Thank you! Cancer Audit Research Database

Dermatoscopy in Routine Practice Chaos & Clues Presented by Dr Cliff Rosendahl & Dr Alan Cameron

(1920) Dermatology Dermatologists Dermatoscope Dermatoscopy

Conflict of interest a method which cannot be taught is barely a method at all.

ALL pigmented lesions Detects malignancy ANY type No need to decide whether melanocytic Can be applied at examination speed Efficacy similar to the other algorithms

What is dermatoscopy? a non-invasive diagnostic technique for skin lesions a low powered microscope designed for visualisation of pigmentation and vessels by reducing the amount of light reflected off the skin surface by either Contact fluid immersion polarising filters

Clinical examination looks at lesions in the horizontal plane In contrast, conventional microscopy looks at lesions in the vertical plane

Because melanin appears as different colours at different depths in the skin dermatoscopy provides information in both the horizontal and vertical planes. It provides a 3-dimensional view Atlas of Dermoscopy Marghoob Braun Kopf. Page 11

What do you put your dermatoscope on? Every lesion? Selected lesions which break the pattern?

Photograph Cliff Rosendahl

Do you need dermatoscopy? Photograph Cliff Rosendahl

Photograph Cliff Rosendahl

Instruments and flight charts

Algorithms 1987 Pehamberger Classic Pattern Analysis 1989 First hand-held dermatoscope consensus meeting metaphoric terminology 1994 Stolz ABCD rule 1996 Menzies method 1998 Argenziano 7 point checklist 2000 Soyer/Argenziano 3 point checklist 2007 CASH (color, architecture, symmetry, and homogeneity) version of pattern Analysis

Do you use Pattern Recognition?

In the next slide I will present 2 images One will be innocent and one suspicious I want you to see how long it takes to decide

Pattern recognition is innate human behaviour Photographs Cliff Rosendahl

In contrast to pattern recognition Pattern analysis is the process of describing and analysing the objects in a logical fashion so they can be defined in a repeatable and teachable manner

Melanocytic Criteria Network Pseudo network Aggregated brown globules Pseudopods/radial streaming Parallel ridge pattern (acral) Homogenous blue pigmentation

Ink spot lentigo Pigmented solar keratosis Solar lentigo/piec Solar lentigo Network occurs in many non-melanocytic lesions

Photographs Cliff Rosendahl Pseudonetwork occurs in facial solar lentigines and facial solar keratoses

Photograph Cliff Rosendahl Aggregated brown globules occur in BCCs Parallel ridge pattern (acral) occurs in corneal haemorrhage Homogenous blue pigmentation occurs in tattoos

Melanocytic Criteria You need a microscope to see melanocytes!

Why a new method??

There is no doubt that the method will have to be improved. There is also no doubt that methods will have to be found to make pattern analysis more objective Pehamberger H, Binder M, Steiner A, Wolff K. In vivo epiluminescence microscopy: improvement of early diagnosis of melanoma. J. Invest. Dermatol. 1993;100(3):356S- 362S.

What makes Pattern Analysis difficult? Lack of clear definitions Descriptions that depend on diagnosis Inconsistent metaphorical terminology No clear diagnostic pathway

Photograph Alan Cameron

2007 Revised pattern Analysis Harald Kittler

Revised Pattern Analysis Rebuilds from the firm foundation of Classic pattern Analysis (no subsequent system gave better results) Iconoclastic - Poorly defined confusing metaphorical language replaced by clearly defined geometric terminology No need to decide melanocytic status as a (hazardous) first step

Towards a more objective Pattern Analysis Descriptions precede diagnosis clear and objectively defined descriptions are the same regardless of diagnosis no metaphoric descriptions A clear structure to reach a diagnosis

Pattern + Colours + Clues = Diagnosis DESCRIPTION PRECEDES DIAGNOSIS! Describing a lesion assists the cognitive process. Metaphoric terms with preconceived diagnostic implications are not used.

Pattern Analysis There are only 5 basic elements.

Lines Reticular Pseudopods Branched Circles parallel Clods Radial Dots Curved

Definitions Line : a two-dimensional continuous object with length greatly exceeding width Pseudopod : a line with a bulbous end Circle : a curved line equidistant from a central point Clod : any well circumscribed, solid object larger than a dot. Clods may take any shape Dot : an object too small to have a discernable shape Structureless : An area with no basic structure predominating

Pattern There are only 5 basic elements. A pattern consists of multiple repetitions of basic elements.

Line a two-dimensional continuous object with length greatly exceeding width. Acral naevus Photograph Alan Cameron

Photograph Alan Cameron

Courtesy Stelios Minas

Photograph Alan Cameron

Pseudopod a line with a bulbous end. Reed naevus Photograph Alan Cameron

Photograph Alan Cameron Circle a curved line equidistant from a central point. Melanoma in situ face

Photograph Alan Cameron Dot an object too small to have a discernable shape. Melanoma courtesy Ian McColl

Clod any well circumscribed, solid object larger than a dot. Clods may take any shape. Invasive melanoma Photograph Alan Cameron

Photographs Alan Cameron

Structureless an area without basic elements, or where no basic element predominates. Photograph Alan Cameron

Pattern + Colours + Clues = Diagnosis

Black Melanin in Stratum corneum, congealed blood Melanin Dark brown Light brown Melanin in the epidermis, dense Melanin in the epidermis, delicate Grey Melanin in the papillary dermis Blue Melanin in the reticular dermis Keratin Orange Yellow Combination of melanin and keratin, serum crust Keratin White Absence of melanin, sclerosis of the dermis, keratin Haemoglobin Red Purple Blood Blood (poorly oxygenized)

Pattern + Colours + Clues = Diagnosis

Pattern + Colours + Clues = Diagnosis Clues to a specific diagnosis Clues to malignancy ( Chaos and Clues )

CLUES TO MALIGNANCY (Chaos and Clues)

each person should develop their own method modified by Jeff Keir

Polygons Photographs Cliff Rosendahl

Evaluating Chaos & Clues Photograph Cliff Rosendahl

Tested on 463 consecutive pigmented lesions in an Australian general practice

CONCLUSIONS A simplified algorithm based on pattern analysis (CHAOS & CLUES) is a useful tool for all types of pigmented lesions, including those which are non-melanocytic Sensitivity - 90.6% Specificity - 62.7%

Asymmetry of structure or colour

Chaos No chaos Judge on pattern and colour, not on outline

Photograph Alan Cameron

Photograph Alan Cameron concentric = no chaos Be suspicious of other combinations of more than one pattern or colour

Photograph Alan Cameron

CHAOS In a Blink! SCAN for CHAOS The presence or absence of CHAOS can usually be assessed at the speed of a blink! With practice it is a scanning assessment If in doubt assume chaos and assess for clues

In contrast to scanning for CHAOS the search for CLUES involves thoughtful examination

1. Eccentric structureless area

Eccentric Structureless Area Any colour except skin colour If white usually represents regression Often scattered grey/blue dots Red- increased blood flow Coloured- dense chaotic melanin deposition

Photograph Cliff Rosendahl

Photographs Cliff Rosendahl

Photograph Alan Cameron

Photograph Cliff Rosendahl

2. Thick lines reticular or branched

Thick Lines Reticular or Branched in benign lesions, the lines are thinner than the holes they enclose Lines thicker than the holes they enclose are seen in melanoma melanomas usually display variability of line thickness

Photographs Cliff Rosendahl

Photograph Alan Cameron

Photographs Alan Cameron

3. Grey or blue structures

Grey or Blue Structures Lines, circles, clods or dots Represent melanin in the dermis Melanoma cells or melanophages or free melanin

Photographs Cliff Rosendahl

Photographs Cliff Rosendahl Dermatomicrographs Richard Williamson Rosendahl C, Cameron A, Bulinska A, Williamson R, Kittler H. Dermatoscopy of a minute melanoma. Australas. J. Dermatol. 2011 Feb;52(1):76 8.

Photograph Cliff Rosendahl

4. Black dots or clods, peripheral

Black Dots or Clods, Peripheral Black dots and clods can occur centrally in naevi. They can occur anywhere in a melanoma, so peripheral black dots and/or clods are a clue to malignancy.

Photograph Alan Cameron Photograph Alan Cameron

Photograph Alan Cameron

Photographs Alan Cameron

Photographs Cliff Rosendahl

5. Lines radial or pseudopods, segmental

Lines Radial or Pseudopods, Segmental Melanocytic lesions: Represent radial proliferation of nests of melanocytes Only requires one pseudopod or 1 radial line Basal cell carcinomas: Radial lines converging

Photographs Cliff Rosendahl

Lines radial segmental also a clue to piec Photographs Cliff Rosendahl

6. White lines

White Lines the colour white is the exception to the rule that structures are defined by pigment. lines are white when they are lighter than surrounding skin Skin coloured lines are occasionally a weak clue- not to be ignored

Photograph Alan Cameron

Photograph Peter Bourne

Photograph Alan Cameron

Photographs Alan Cameron

Nodular melanomas may be symmetrical Photographs Cliff Rosendahl

7. Polymorphous vessels

Polymorphous Vessels A relatively weak clue (pigment structures should take priority when present) More than one vessel pattern Dot vessels often seen in melanomas

Vessel patterns Vessel structure left: A- dots; B- clods; C- lines; D- looped; E- curved; F- serpentine; G- helical; H- coiled Vessel arrangement right: A- random; B- clustered; C- serpiginous, D- linear; E- centred; F- radial; G -reticular; H- branched

Photograph Cliff Rosendahl

Looped Serpentine Helical Photograph Cliff Rosendahl

Photographs Cliff Rosendahl

Photograph Cliff Rosendahl

Photographs Cliff Rosendahl

Photograph Cliff Rosendahl

8. Lines parallel, ridges (acral) or chaotic (nails)

Lines parallel, ridges (acral) or chaotic (nails) Acral skin has a pattern of pattern of ridges and furrows Pigmentation tends to follow either the ridges or the furrows, creating parallel lines In naevi, pigment follows the furrows

Photograph Alan Cameron

Photograph Alan Cameron Photograph Alan Cameron

Lines parallel, ridges (acral) or chaotic (nails) Acral skin has a pattern of pattern of ridges and furrows Pigmentation tends to follow these ridges and furrows Pigmentation on the ridges is a clue to melanoma even in a symmetrical lesion

courtesy Jean-Yves Gourhant

Photographs Alan Cameron

Lines parallel, ridges (acral) or chaotic (nails) Lines parallel on nails, varying in width interval and colour

Photograph Cliff Rosendahl

1 Poster 1 smart kid + = 1 rare in-situ melanoma

Excluding seborrhoeic keratoses

Photograph Alan Cameron

Excluding seborrhoeic keratoses Multiple orange or yellow clods Multiple white clods Thick curved or reticular lines Well demarcated border Vessels as loops Multiple grouped similar lesions Malignant conditions can have individual criteria Weigh the clues to arrive at a diagnosis If in doubt at all - BIOPSY

Photograph Alan Cameron

Photographs Alan Cameron

Photograph Alan Cameron

The Aoraki Principle If with respect to any skin lesion you remain unable to make a CONFIDENT SPECIFIC BENIGN Diagnosis BIOPSY IS INDICATED Photograph Cliff Rosendahl

Photographs Cliff Rosendahl

Photograph Cliff Rosendahl Level 1 melanoma No clues to malignancy but he was not aware how long it had been there

Chaos and Clues in everyday practice

Exceptions

Photographs Alan Cameron

Photograph Alan Cameron

The most valuable clinical sign of all

The break in the pattern The almost inaudible snap of a twig

Photographs Cliff Rosendahl Photograph Cliff Rosendahl

Photograph Cliff Rosendahl

The signature of an assassin Melanoma writes its message on the skin with its own ink and it is there for all to see Dr Neville Davis Modern concepts of melanoma and its management Annals of Plastic Surgery 1978:1:625-630

Look for the break in the pattern Scan for chaos Examine for clues

Take out the assassin

If there is more than one way to skin a cat why not choose the easiest method? Harald Kittler

If there is more than one way to skin a cat why not choose the easiest method? Harald Kittler Thank you!