DERMATOLOGY PRACTICAL & CONCEPTUAL www.derm101.com Research | Dermatol Pract Concept 2012;2(2):12 55 BLINCK—A diagnostic algorithm for skin cancer diagnosis combining clinical features with dermatoscopy findings Peter Bourne, MBBS1, Cliff Rosendahl, MBBS1, Jeff Keir MBBS2,3, Alan Cameron, MBBS1 1 School of Medicine, University of Queensland, Brisbane, Australia 2 Department of Dermatology, School of Medicine, Cardiff University, Wales 3 Northern Rivers Skin Cancer Clinic, Ballina, NSW, Australia Key words: melanoma, skin cancer, diagnostic algorithm, BLINCK, primary care Citation: Bourne P, Rosendahl C, Keir J, Cameron A. BLINCK—A diagnostic algorithm for skin cancer diagnosis combining clinical features with dermatoscopy findings. Dermatol Pract Conc. 2012;2(2):12. http://dx.doi.org/10.5826/dpc.0202a12. Received: October 30, 2011; Accepted: February 20, 2012; Published: April 30, 2012 Copyright: ©2012 Bourne et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: None. Competing interests: All authors declare no conflict of interest with regards the preparation or writing of this paper. They have not accepted from a sponsor, pharmaceutical company or other organization any funds for research, consultancy fees, fellowship/research/ education grants, nor hold any stock or shares in any entity that may gain financial benefit or detriment as a result of the deliberations set out in or the conclusions of the study. All authors have contributed significantly to this publication. Corresponding author: Peter Bourne, Skin Cancer Clinic of Toowoomba, Suite 10, 9 Scott St, Toowoomba, Queensland 4350, Australia. Tel. 07 46 130333; Fax. 07 46 130055.Email: peter_bourne@bigpond.com. Background: Deciding whether a skin lesion requires biopsy to exclude skin cancer is often challeng- ing for primary care clinicians in Australia. There are several published algorithms designed to assist with the diagnosis of skin cancer but apart from the clinical ABCD rule, these algorithms only evalu- ate the dermatoscopic features of a lesion. Objectives: The BLINCK algorithm explores the effect of combining clinical history and examination with fundamental dermatoscopic assessment in primary care skin cancer practice. Patients/Methods: Clinical and dermatoscopic images of 50 skin lesions were collected and shown to four primary care practitioners. The cases were assessed by each participant and lesions requiring biopsy were determined on separate occasions using the 3-Point Checklist, the Menzies method, clini- cal assessment alone and the BLINCK algorithm. Results: The BLINCK algorithm had the highest sensitivity and found more melanomas than any of the other methods. However, BLINCK required more biopsies than the other methods. When com- paring diagnostic accuracy, there was no difference between BLINCK, Menzies method and clinical assessment but all were better than the 3-Point checklist. Conclusions: These results suggest that the BLINK algorithm may be a useful skin cancer screening tool for Australian primary care practice. ABSTRACT 56 Research | Dermatol Pract Concept 2012;2(2):12 Introduction Most GP skin cancer training courses in Australia encour- age beginners to use dermatoscopy algorithms when decid- ing if a lesion requires biopsy to exclude skin cancer. Indeed, the ability to recognise dermatoscopic criteria correctly and apply a dermatoscopic algorithm is often seen as the sine qua non of excellence in primary care skin cancer practice. The benefits of using a scored “dermatoscopy-only” algo- rithm are well documented [1,2]. However, this approach does not score often useful clinical information such as his- tory of lesion change, the “ugly duckling” sign [3,4] and even the patient’s own instinct regarding the lesion. The authors feel that a more “holistic” diagnostic approach, where these clinical aspects are also scored, may reduce the chances of the student missing less obvious skin cancers. Methods We performed a retrospective analytical trial to see if a new algorithm, incorporating clinical as well as dermatoscopic cri- teria, was any different to the three methods commonly used in Australia primary care practice to diagnose skin cancer. The new algorithm, BLINCK, was developed and compared to two “dermatoscopy-only” algorithms, (the 3-Point Check- list and the Menzies method), and clinical assessment alone. The BLINCK algorithm was designed as an assessment tool for primary care skin cancer clinicians and does not require the user to be an “expert” in dermatoscopy. In contrast to most existing algorithms, the distinction between melano- cytic and non-melanocytic [5] lesions is not necessary and both pigmented and non-pigmented lesions may be assessed. The acronym, BLINCK, refers to six questions that should be asked when assessing a skin lesion and includes both clinical and dermatoscopic features. B – Benign: Is the lesion immediately recognisable as a common benign tumour, on clinical and dermatoscopic examination, with other similar lesions being present on that part of the body, e.g., typical solar lentigo, seborrheic keratosis, haemangioma or dermatofibroma? If ‘yes’, no further action is required. If ‘no’, then proceed to the following four questions. L – Lonely: Is this lesion, clinically and dermatoscopically, the only one of its type on that region of the body, i.e., an “out- lier” or “ugly duckling”? ‘Yes’ scores 1. I – Irregular: For pig- mented lesions, is the lesion dermatoscopically irregular, that is, does it have an asymmetrical pigmentation pattern and more than one colour? For non-pigmented lesions, is there an irregular vascular pattern? ‘Yes’ scores 1. N – Nervous: Is the patient nervous or concerned that this particular lesion may be a skin cancer? (This excludes the “generally anxious” patient or patients with hypochondriasis). C – Change: Does the patient, or another observer, feel that the lesion is chang- ing? (Note that only a total score of 1 can be given if either or both of these last two questions are answered ‘yes’.) K – Known clues: Does the lesion definitely have any one of the following dermatoscopic “clues” to malignancy? • Atypical network—unmistakable variation in thickness of network line • Pseudopods or streaks—segmental • Black dots, globules or clods—irregular and peripheral • Eccentric structureless zone • Blue or grey colour—irregular distribution • Vessels—1. Polymorphous; 2. finely focused and arboriz- ing; 3. glomerular (coiled) shaped • Acral lesions—1. parallel ridge pattern; 2. diffuse irregular brown/black pigmentation ‘Yes’ to any one of these scores 1 (maximum score of 1). A total score of 2 or more out of 4 requires biopsy. To compare BLINCK with the other diagnostic methods a pilot trial was conducted using images of skin lesions typically seen in Australian primary care skin cancer practice. From June 1 to July 6, 2009, all skin lesions consecutively excised to exclude skin cancer were recorded by an experienced skin cancer doctor, (A.C.), working in a dedicated skin cancer prac- tice in Brisbane, Australia. Clinically obvious basal cell carci- nomas which could be easily diagnosed without dermoscopy were not included in the collection set. High quality clini- cal and dermatoscopic photographs of 50 skin lesions were obtained, (non-polarised dermatoscopic images taken with a non-polarised Dermlite Foto attachment, or Dermlite Fluid dermatoscope, (3Gen, LLC), and Canon D40 digital camera, (Tokyo, Japan). Written patient consent was obtained in every case and any history of lesion change or patient concern was documented, as well as whether the lesion was thought to be an “ugly duckling” by the original examiner. As common lesions such as the dermatofibroma, seborrhoeic keratosis and congenital naevus sometimes pose a diagnostic challenge for inexperienced clinicians, an example of each, seen during the collection period, was included in the set of 50. These three cases were assessed as being obviously benign by A.C. and not biopsied. As well, a flat naevus that was unchanged on sequential digital monitoring was included in the set without biopsy. Histopathological examination of the other 46 lesions revealed 19 to be skin cancers with nine being melanomas (eight in situ and one invasive). Figures 1 and 2 show an example of a melanoma case from the trial. Four primary care clinicians, (three GPs and a clinical nurse), with varying levels of dermatoscopic experience, were asked to review the photographs and select which lesions were suspicious for malignancy, hence requiring biopsy. This assessment was done on four occasions, each time using a different diagnostic approach. The following methods were used in this order. 1. 3-Point Checklist—Only dermatoscopic images were shown. Research | Dermatol Pract Concept 2012;2(2):12 57 Figure 1. Despite being dermatoscopically bland, this lesion had changed and was “lonely,” scoring 2 in the BLINCK method and mandating biopsy. Histopathology is shown demonstrating melano- ma in situ. A: Clinical view. B: Macro view. C: Dermatoscopic view. [Copyright: ©2012 Bourne et al.] Figure 2. Dermatoscopic view. A: Histology slide 1. B: Histology slide 2. C: Histology slide 3. [Copyright: ©2012 Bourne et al.] A C B 58 Research | Dermatol Pract Concept 2012;2(2):12 2. Menzies method—Only dermatoscopic images were shown. 3. Clinical assessment alone—Only clinical images were shown. 4. BLINCK—Dermatoscopic and clinical images were sup- plied as well as information regarding reported lesion change, “ugly duckling” sign or patient concern as recorded by original examiner. The clinicians received prior instruction on the use of the three algorithms, and Excel answer sheets for each method listed the various criteria used in that algorithm. The clini- cians were asked to decide if these criteria were present or not and the spreadsheet was used to calculate the results. The clinician’s response for each case was compared to the correct diagnosis and graded as true positive, false negative, false pos- itive or true negative. The number of cancers and melanomas correctly detected and the number of biopsies indicated for each clinician and each method were also recorded (Table 1). Four clinicians using four methods resulted in 16 con- tingency tables for sensitivity and specificity. As two of the methods related only to pigmented lesions, (3-Point and Menzies), the five non-pigmented specimens in the set of 50 were excluded from the contingency tables for these meth- ods. Specificity, sensitivity and diagnostic accuracy were calculated according to standard formula. Analysis of vari- ance (ANOVA) was used with the LSD test, (least significant difference test), to detect differences between clinicians and methods. A P-value of <0.05 indicated statistical significance. The means for specificity, sensitivity and diagnostic accuracy are shown with their 95% Confidence Interval, (95% CI). We used the Statistica software package for statistical analysis. Results There were no differences between the clinicians regarding sensitivity, specificity, diagnostic accuracy, number of can- TABLE 1. True and false positives and negatives for the four methods by the four clinicians with sensitivity, specificity, melanomas found and biopsies indicated. Clinician Method True Pos False Neg False Pos True Neg Sens. Spec. Number melanomas found Number biopsies indicated P.B. 3point 11 23 5 6 68.8 20.7 6 34 Menzies 6 8 10 21 37.5 72.4 2 14 Clinical 9 5 10 26 47.3 83.9 2 14 BLINCK 19 13 0 18 100 58.1 9 32 C.R. 3point 11 18 5 11 68.7 37.9 6 29 Menzies 10 6 6 23 62.5 79.3 5 16 Clinical 13 14 6 17 68.4 54.8 3 27 BLINCK 19 23 0 8 100 25.8 9 42 D.B. 3point 11 18 5 11 68.8 37.9 5 29 Menzies 11 14 5 15 68.8 51.7 6 25 Clinical 9 6 10 25 47.4 80.6 2 15 BLINCK 16 15 3 16 84.2 51.6 8 31 H.C.   3point 5 8 11 21 31.3 72.4 2 13 Menzies 8 8 8 21 50 72.4 3 16 Clinical 9 9 10 22 47.4 80 2 18 BLINCK 15 11 4 20 78.9 64.5 7 26 Research | Dermatol Pract Concept 2012;2(2):12 59 cers detected, number of melanomas found or biopsies indi- cated, however, there were significant differences between the four methods (Table 2). BLINCK had higher sensitiv- ity and found significantly more melanomas than the other three methods. However, the Menzies method and clinical only approach had higher specificity and resulted in fewer biopsies than BLINCK. Diagnostic accuracy was the same for BLINCK, Menzies and clinical only, and all were better than the 3-Point checklist. BLINCK had higher sensitivity, diagnostic accuracy, number of cancers found and number of melanomas found than the 3-Point checklist, but had similar specificity and number of biopsies required. The 50 lesions used in the trial were sourced from 46 patients, 22 male and 24 female, with ages varying between 30 and 60 years (average 58 years). Anatomical sites of lesions are shown in Table 3. Four clinically benign lesions were included in the set without a histological diagnosis, (dermatofibroma, sebor- rhoeic keratosis, congenital naevus and monitored flat nae- vus), and the remainder were subjected to histological exam- ination (Table 4). Discussion Australia has the highest rate of melanoma in the world [6]. It is the third most common cancer in Australia in both men and in women [7]. Approximately two out of every three Australians will be diagnosed with skin cancer before the age of 70 [8] and roughly a million GP visits are made annu- ally for skin cancer. This makes skin cancer the most expen- sive of all cancers for the Australian health system [9, 10]. More skin cancers are diagnosed and treated in Australia by primary care doctors than by medical specialists [11]. These generalists require a simple yet accurate screening tool that will allow the detection of melanoma and other skin cancers at an early stage when complete cure is possible. Currently, most introductory skin cancer courses in Australia endorse dermatoscopic evaluation of suspicious skin lesions as the preferred screening method, commonly using the 3-Point checklist or the Menzies method [12,13]. Other clinical features that may assist with the diagnosis of skin cancer have been previously studied. The “ugly duck- TABLE 2. Mean values of sensitivity, specificity and diagnostic accuracy with 95% Confidence Intervals (CI) are shown, as well as numbers of melanomas and cancers found and biopsies required. Means followed by the same letter in each column were not significantly different.   Sensitivity (95% CI) Specificity (95% CI) Diagnostic Accuracy (95% CI) Melanomas found (9 total) Total cancers found (19 total) Number biopsies (50 total) 3-point 59.4a (52.2-66.5) 42.2a (35.0-49.4) 48.3a (44.7-52.0) 5b 9a 26ab Menzies 54.7a (47.4-62.0) 69ab (62.2-75.7) 63.9b (60.4-67.3) 4ab 9a 18a Clinical 52.6a (40.1-54.7) 74.8b (74.0-85.7) 65.0b (61.5-68.5) 2a 10a 18a BLINCK 90.8b (86.5-95.0) 50ab (42.7-57.3) 65.5b (62.1-69.8) 8c 17b 33b TABLE 3. Anatomical location of lesions Location Number face 8 neck 1 chest 3 back 21 shoulder 2 arm 3 thigh 4 leg 7 foot plantar 1 60 Research | Dermatol Pract Concept 2012;2(2):12 ling” sign has been shown to be of possible use in melanoma screening [4]. Importantly, the ability to assess whether a lesion is “different” from surrounding lesions does not appear to require advanced training. Hence, it would seem sensible that primary care clinicians seek out “ugly duckling” lesions when performing a skin examination, (“Lonely” in the BLINCK algorithm). Lesion change is also known to be associated with malignancy, particularly in patients over 50 years of age [14], and consideration of this clinical feature would also seem prudent. A disproportionate amount of concern for a lesion by the patient, (“Nervous”), may have significance for two reasons. Firstly, patients may be uncer- tain if their lesion has changed or perhaps they may simply fail to volunteer the history of change, bleeding, itch or sore- ness. They suspect that it is a cancer but assume the doctor is able to make the diagnosis by mere inspection without needing any clinical history. However, this history may be the only clue to malignancy in dermatoscopically bland lesions, and a false negative diagnosis may be made using dermato- scopic assessment alone. Secondly, dismissing a lesion about which the patient is quite concerned may have medico-legal consequences should it prove later to be malignant. In this small trial, the BLINCK algorithm, which scored these extra clinical features along with basic dermatoscopic assessment, found more skin cancers and melanomas than the commonly endorsed methods in Australia. However, more excisions were required to achieve this result. This raises the question as to what is the best measure of “accu- racy” in melanoma diagnosis. Argenziano has suggested that NNE, (number of melanocytic lesions needed to be excised in order to find one melanoma), may be useful for measur- ing accuracy in melanoma detection and compared the NNE in specialised and non-specialised clinical settings [15]. In his study the NNE reduced over time from 12.8 to 6.8 with specialised clinics but remained unchanged at 29.4 in non- specialised centres. This would seem to suggest that a level around 6.8 may be an appropriate goal for skin cancer clini- cians. In our study, the overall NNE for melanoma by all cli- nicians using the BLINCK algorithm was 6, with the 3-Point checklist 11, the Menzies method 13 and clinical assessment only 22, suggesting that BLINCK may have value as a skin cancer screening tool. As this trial was limited by the small number of skin cancers and melanomas, and by the fact that it was a vir- tual study without direct assessment of patients’ lesions, it is difficult to draw definite conclusions regarding the benefits of combining clinical with dermatoscopic features in one diagnostic algorithm. Indeed, it could be said that clinicians using dermatoscopic-only algorithms implicitly incorporate relevant clinical aspects of the case in their decision making process. 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