What is the role of dermoscopy in melanoma diagnosis?
Dermoscopy (dermatoscopy, surface microscopy, epiluminescence microscopy) is a technique that uses a hand-held magnifying device combined with either the application of a liquid between the transparent plate of the device and the skin, or the use of cross-polarised light. This technique allows the visualisation of diagnostic features of pigmented skin lesions that are not seen with the naked eye.
Summary of systematic review results
Meta-analyses performed on studies in a variety of clinical and experimental settings have shown that using dermoscopy improves diagnostic accuracy for melanoma. From a meta-analysis of nine level II diagnostic studies subject to varying degrees of verification bias performed prospectively in a clinical setting the diagnostic accuracy for melanoma, as expressed by the relative diagnostic odds ratio, was 15.6 (95% CI 2.9–83.7) times higher for dermoscopy compared with naked eye (clinical) examination. Importantly, the meta-analysis was restricted to studies that directly compared the two methods within each study. Sensitivity of dermoscopy was 18% (95% CI 9%–27%; P=0.002) higher than for naked eye examination, but there was no evidence of an effect on specificity (9% higher for dermoscopy; P=0.18). Subsequent to this meta-analysis one level II study has been published in a primary care setting showing results consistent with the meta-analysis (42% increase in sensitivity and 5% increase in specificity with dermoscopy compared to naked eye). However, there was a significant improvement in the confidence of diagnosis of both true melanoma (17% increase) and true non-melanoma (16% increase) with dermoscopy. In a further randomized clinical trial in primary care of both pigmented and non-pigmented lesions the odds ratio for a correct diagnosis in the dermoscopy compared to naked eye group was 1.51 (95% CI:0.96-2.37, p=0.07). Again, consistent with the meta-analysis, the effect was greater for the diagnosis of melanoma (61.5% sensitivity using dermoscopy versus 22.2% for naked-eye).
Specificity can also be examined by its effect on excision rates of benign lesions, which was not addressed in the meta-analysis. Two such studies suggest reduced rates of excision of benign lesions using dermoscopy (reduced benign to malignant ratio of excised lesions and reduction of patients referred to biopsy) and provide indirect evidence for improved specificity in a specialist setting. The addition of dermoscopy to naked eye (clinical) examination has also been shown to reduce excisions of benign pigmented lesions in high-risk patients in a specialist setting and routinely managed pigmented lesions in primary care.
While there are fewer studies on dermoscopy in primary care (general practice), all five that were undertaken in this context (one study with both general practitioners and inexperienced specialists or trainees) show a consistently improved sensitivity for the diagnosis of melanoma or the identification of suspicious lesions requiring biopsy. It should be noted that all the studies cited were undertaken by clinicians with some training in dermoscopy (restricted to lectures or reading material in some studies). For this reason, and based on other evidence where lack of training can lead to a reduction of diagnostic accuracy some formal training in dermoscopy is required to achieve improvement in diagnostic accuracy.
Dermoscopy can also identify diagnostic features in non-pigmented (amelanotic) lesions.
Evidence summary and recommendations
|From a meta-analysis of nine level II studies prospectively performed in a clinical setting, the diagnostic accuracy for melanoma, as expressed by the relative diagnostic odds ratio, was 15.6 times higher for dermoscopy compared with naked eye examination. Sensitivity of dermoscopy was 18% (95% CI 9%–27%; P=0.002) higher than for eye examination, but there was no evidence of an effect on specificity. Two subsequent level II studies showed results consistent with the larger meta-analysis.+||I, II||, , , , , , , , , , , , |
|Dermoscopy has been shown to reduce the benign:malignant ratio of excised melanocytic lesions and reduce the number of patients referred for biopsy in both specialists and primary care.+||II||, , , |
+The studies were classified as III-2 according the NHMRC 2009 levels and grade of evidence. Using the Grade approach, the studies were then upgraded to level II if the only criteria not meeting level II was the pathologist was not blinded to clinical information of the patient/lesion since it is established that clinical information is required for an accurate pathological diagnosis of melanocytic lesions.
|Clinicians who are performing skin examinations for the purpose of detecting skin cancer should be trained in and use dermoscopy.||A|
- ↑ Kittler H, Marghoob AA, Argenziano G, Carrera C, Curiel-Lewandrowski C, Hofmann-Wellenhof R, et al. Standardization of terminology in dermoscopy/dermatoscopy: Results of the third consensus conference of the International Society of Dermoscopy. J Am Acad Dermatol 2016 Jun;74(6):1093-106 Available from: http://www.ncbi.nlm.nih.gov/pubmed/26896294.
- ↑ Watts CG, Dieng M, Morton RL, Mann GJ, Menzies SW, Cust AE. Clinical practice guidelines for identification, screening and follow-up of individuals at high risk of primary cutaneous melanoma: a systematic review. Br J Dermatol 2015 Jan;172(1):33-47 Available from: http://www.ncbi.nlm.nih.gov/pubmed/25204572.
- ↑ Carrera C, Marchetti MA, Dusza SW, Argenziano G, Braun RP, Halpern AC, et al. Validity and Reliability of Dermoscopic Criteria Used to Differentiate Nevi From Melanoma: A Web-Based International Dermoscopy Society Study. JAMA Dermatol 2016 Apr 13 Available from: http://www.ncbi.nlm.nih.gov/pubmed/27074267.
- ↑ Argenziano G, Giacomel J, Zalaudek I, Blum A, Braun RP, Cabo H, et al. A clinico-dermoscopic approach for skin cancer screening: recommendations involving a survey of the International Dermoscopy Society. Dermatol Clin 2013 Oct;31(4):525-34, vii Available from: http://www.ncbi.nlm.nih.gov/pubmed/24075542.
- ↑ Kittler H, Pehamberger H, Wolff K, Binder M. Diagnostic accuracy of dermoscopy. Lancet Oncol 2002 Mar;3(3):159-65 Available from: http://www.ncbi.nlm.nih.gov/pubmed/11902502.
- ↑ Bafounta ML, Beauchet A, Aegerter P, Saiag P. Is dermoscopy (epiluminescence microscopy) useful for the diagnosis of melanoma? Results of a meta-analysis using techniques adapted to the evaluation of diagnostic tests. Arch Dermatol 2001 Oct;137(10):1343-50 Available from: http://www.ncbi.nlm.nih.gov/pubmed/11594860.
- ↑ 7.0 7.1 7.2 Argenziano G, Puig S, Zalaudek I, Sera F, Corona R, Alsina M, et al. Dermoscopy improves accuracy of primary care physicians to triage lesions suggestive of skin cancer. J Clin Oncol 2006 Apr 20;24(12):1877-82 Available from: http://www.ncbi.nlm.nih.gov/pubmed/16622262.
- ↑ 8.0 8.1 8.2 8.3 Carli P, de Giorgi V, Chiarugi A, Nardini P, Weinstock MA, Crocetti E, et al. Addition of dermoscopy to conventional naked-eye examination in melanoma screening: a randomized study. J Am Acad Dermatol 2004 May;50(5):683-9 Available from: http://www.ncbi.nlm.nih.gov/pubmed/15097950.
- ↑ 9.0 9.1 9.2 9.3 Carli P, De Giorgi V, Crocetti E, Mannone F, Massi D, Chiarugi A, et al. Improvement of malignant/benign ratio in excised melanocytic lesions in the 'dermoscopy era': a retrospective study 1997-2001. Br J Dermatol 2004 Apr;150(4):687-92 Available from: http://www.ncbi.nlm.nih.gov/pubmed/15099364.
- ↑ 10.0 10.1 Carli P, Mannone F, De Giorgi V, Nardini P, Chiarugi A, Giannotti B. The problem of false-positive diagnosis in melanoma screening: the impact of dermoscopy. Melanoma Res 2003 Apr;13(2):179-82 Available from: http://www.ncbi.nlm.nih.gov/pubmed/12690302.
- ↑ 11.0 11.1 Bono A, Bartoli C, Cascinelli N, Lualdi M, Maurichi A, Moglia D, et al. Melanoma detection. A prospective study comparing diagnosis with the naked eye, dermatoscopy and telespectrophotometry. Dermatology 2002;205(4):362-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/12444332.
- ↑ 12.0 12.1 Bono A, Tolomio E, Trincone S, Bartoli C, Tomatis S, Carbone A, et al. Micro-melanoma detection: a clinical study on 206 consecutive cases of pigmented skin lesions with a diameter < or = 3 mm. Br J Dermatol 2006 Sep;155(3):570-3 Available from: http://www.ncbi.nlm.nih.gov/pubmed/16911283.
- ↑ 13.0 13.1 Benelli C, Roscetti E, Pozzo VD, Gasparini G, Cavicchini S. The dermoscopic versus the clinical diagnosis of melanoma. Eur J Dermatol 1999 Sep;9(6):470-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/10491506.
- ↑ 14.0 14.1 Cristofolini M, Zumiani G, Bauer P, Cristofolini P, Boi S, Micciolo R. Dermatoscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions. Melanoma Res 1994 Dec;4(6):391-4 Available from: http://www.ncbi.nlm.nih.gov/pubmed/7703719.
- ↑ 15.0 15.1 Dummer W, Doehnel KA, Remy W. [Videomicroscopy in differential diagnosis of skin tumors and secondary prevention of malignant melanoma]. Hautarzt 1993 Dec;44(12):772-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/8113040.
- ↑ 16.0 16.1 Stanganelli I, Serafini M, Bucch L. A cancer-registry-assisted evaluation of the accuracy of digital epiluminescence microscopy associated with clinical examination of pigmented skin lesions. Dermatology 2000;200(1):11-6 Available from: http://www.ncbi.nlm.nih.gov/pubmed/10681607.
- ↑ 17.0 17.1 17.2 Vestergaard ME, Macaskill P, Holt PE, Menzies SW. Dermoscopy compared with naked eye examination for the diagnosis of primary melanoma: a meta-analysis of studies performed in a clinical setting. Br J Dermatol 2008 Sep;159(3):669-76 Available from: http://www.ncbi.nlm.nih.gov/pubmed/18616769.
- ↑ 18.0 18.1 18.2 18.3 18.4 Menzies SW, Emery J, Staples M, Davies S, McAvoy B, Fletcher J, et al. Impact of dermoscopy and short-term sequential digital dermoscopy imaging for the management of pigmented lesions in primary care: a sequential intervention trial. Br J Dermatol 2009 Dec;161(6):1270-7 Available from: http://www.ncbi.nlm.nih.gov/pubmed/19747359.
- ↑ 19.0 19.1 19.2 19.3 Koelink CJ, Vermeulen KM, Kollen BJ, de Bock GH, Dekker JH, Jonkman MF, et al. Diagnostic accuracy and cost-effectiveness of dermoscopy in primary care: a cluster randomized clinical trial. J Eur Acad Dermatol Venereol 2014 Nov;28(11):1442-9 Available from: http://www.ncbi.nlm.nih.gov/pubmed/25493316.
- ↑ 20.0 20.1 van der Rhee JI, Bergman W, Kukutsch NA. Impact of dermoscopy on the management of high-risk patients from melanoma families: a prospective study. Acta Derm Venereol 2011 Jun;91(4):428-31 Available from: http://www.ncbi.nlm.nih.gov/pubmed/21625824.
- ↑ 21.0 21.1 Dolianitis C, Kelly J, Wolfe R, Simpson P. Comparative performance of 4 dermoscopic algorithms by nonexperts for the diagnosis of melanocytic lesions. Arch Dermatol 2005 Aug;141(8):1008-14 Available from: http://www.ncbi.nlm.nih.gov/pubmed/16103330.
- ↑ Westerhoff K, McCarthy WH, Menzies SW. Increase in the sensitivity for melanoma diagnosis by primary care physicians using skin surface microscopy. Br J Dermatol 2000 Nov;143(5):1016-20 Available from: http://www.ncbi.nlm.nih.gov/pubmed/11069512.
- ↑ Binder M, Puespoeck-Schwarz M, Steiner A, Kittler H, Muellner M, Wolff K, et al. Epiluminescence microscopy of small pigmented skin lesions: short-term formal training improves the diagnostic performance of dermatologists. J Am Acad Dermatol 1997 Feb;36(2 Pt 1):197-202 Available from: http://www.ncbi.nlm.nih.gov/pubmed/9039168.