What is Dermoscopy? Early Dermoscopes. Deciphering Dermoscopy: Terminology, Features & Algorithms 6/17/2018

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1 Deciphering Dermoscopy: Terminology, Features & Algorithms Where did it come from and why do we use it? Jennie T. Clarke, MD Associate Professor of Dermatology University of Utah School of Medicine What is Dermoscopy? AKA - epiluminescence microscopy, epillumination microscopy, skin surface microscopy incident microscopy, dermatoscopy Non-invasive technique for evaluation of skin lesions Low-powered microscopy (10X) that allows visualization of features below the stratum corneum to the superficial dermis Early Dermoscopes Binocular Dermoscopy (1921) Johann Saphier First Portable Handheld Dermoscopy (1958) Leon Goldman Saphier J. (1921). Die dermatoskopie. IV. Mitteilung. Archiv für Dermatologie und Syphilis. 136(2), Lee & Hirokawa. Clinics in Dermatology (2010) 28,

2 Non-Polarized Dermoscope Present Day Dermoscopes Dual Polarized/ Non-polarized Dermoscope Polarized Dermoscope (There are a number of manufacturers, I do not endorse any specific brand) Why Should I Use Dermoscopy? One is easily disoriented amidst a puzzling amount of terminology, signs, and algorithms. At times, one cannot help but conclude that the subtleties and nuances of dermatoscopy can be only mastered by those who dedicate an inordinate amount of time and effort to the science - Lee & Hirokawa. Clinics in Dermatology. 2010;28: Which of the following statements about dermoscopy is TRUE? A. Dermoscopy does NOT improve the sensitivity for detecting melanoma in pigmented lesion clinics B. Dermoscopy improves diagnostic accuracy among untrained dermatologists C. Dermoscopy decreases the number of benign lesions biopsied in experienced hands D. Dermoscopy increases the sensitivity for detecting melanoma but also increases the number of biopsies performed overall 2

3 Which of the following statements about dermoscopy is TRUE? A. Dermoscopy does NOT improve the sensitivity for detecting melanoma in pigmented lesion clinics B. Dermoscopy improves diagnostic accuracy among untrained dermatologists C. Dermoscopy decreases the number of benign lesions biopsied in experienced hands D. Dermoscopy increases the sensitivity for detecting melanoma but also increases the number of biopsies performed overall Dermoscopy Improves Diagnostic Accuracy Sensitivity - the proportion of melanomas correctly identified by dermoscopy Dermatologists correctly diagnosis 65-80% of melanomas with unaided eye. Dermoscopy can increase accuracy by 10-27% (Kittler, Lancet Oncol, 2002) Pre-training diagnostic accuracy of primary care physicians - slightly better than chance. Post-training significant improvement in melanoma diagnosis with dermoscopy vs. unaided eye (Westerhoff, Br. J Dermatol 2000) Diagnostic accuracy of untrained dermoscopists is worse than accuracy without dermoscopy (Binder, Arch Dermatol, 1995) Dermoscopy Reduces Unneeded Biopsies Specificity - the proportion of benign pigmented lesions correctly identified by dermoscopy 42% in biopsy following exam with dermoscopy + unaided eye compared with unaided eye alone (Carli, J Amer Acad Dermatol, 2004) Ratio of benign:malignant excised melanocytic lesions decreased from 18:1 pre-dermoscopy training to 4:1 posttraining, while non-dermoscopists performance did not improve during same 4 year time period (12:1 to 14:1). (Carli, Br J Dermatol, 2004). 3

4 Why Should I Use Dermoscopy? Dermoscopic examination is quick & non-invasive Dermoscopy often helps to reassure patients Dermoscopy helps identify suspicious areas in large lesions to aid in biopsy and to assess borders before excision Dermoscopy reduces unnecessary biopsies Dermoscopy significantly improves accuracy of melanoma diagnosis Role of Dermoscopy Dermoscopy is an adjunct to history and clinical examination Do not disregard clinical information that suggests malignancy due to equivocal dermoscopy If in doubt, BIOPSY How Does Dermoscopy Work? Non-polarized Dermoscopy Uses a liquid interface between glass plate and skin to reduce reflection of light from skin surface thereby making the stratum corneum more translucent 70% alcohol (Best choice for skin) Hand-sanitizing gel (Best for nails), ultrasound gel, mineral oil, water Dual Devices Polarized Dermoscopy When switching Uses cross polarization between polarized & to capture backscatter nonpolarized the scope of light from deeper should be in contact layers of skin with a liquid interface. Eliminates need for If not, you ll see only a liquid interface and magnified image of the direct contact with skin lesion in the nonpolarized mode & dermoscopic structures only in the polarized mode 4

5 How Does Dermoscopy Work? How Does Dermoscopy Work? Polarized Non-polarized Colors & Structures Black: melanin in stratum corneum Brown: melanin in epidermis Gray: melanin in papillary dermis Blue: melanin in reticular dermis Red: blood Yellow: keratin White: collagen, keratin, absence of melanin 5

6 Polarized or Non-polarized What s the Difference? Non-polarized Blue-white color & milialike cysts better visualized (these are superficial features) Pressure can compress vessels Polarized Blood vessels & white shiny areas (chysalis sturcture) better visualized (these are deeper features) Blind to objects mm in depth, but better visualization of deeper structures Compression Non-polarized Polarized Seborrheic Keratosis Milia-like cysts Basal Cell Carcinoma Arborizing vessels Melanoma Chrysalis structures 6

7 So, How do I Get Started? ---With a little help from Dr. Kirby dermoscopy.wordpress.com/2015/10/29 7

8 Colors in Dermoscopy Margoob A, et al. Atlas of Dermoscopy. Weisman K, et al. JAMA Derm. 2006;142(5):1250 Dermatoscopes Dermatoscopes Dermatoscope = Lens (10-14X) + Light Dermlite (3Gen) Handyscope (Fotofinder) DermScope (Canfield) 8

9 For a really fun time Dermoscopic Algorithms Algorithms Many exist and often focus on pigmented lesions Sensitivity: 80-92% (correctly finds) Specificity: 60-66% (correctly excludes) ABCD rule of dermatoscopy; Seven-point checklist; 3-point checklist; CASH algorithm 9

10 A Simple Approach to Dermoscopy: The 2-Step Algorithm If it doesn t fit, It has to split Marghoob, A. A. et al. Arch Dermatol 2010;146: Yes Observe Yes Step 2. Fit a Benign Nevus Pattern? Does it Fit? Step 1: Melanocytic? pigment network, globules, homogeneous? No Yes Melanoma Biopsy/Excise Step 3. Are there Melanoma Features? No No Step 2. Structures seen in DF, BCC, SK, Angioma, SCC? Concerning: Excise or Short-term monitoring Does it Fit? Step 1: Melanocytic? -pigment network or -globules or -homogeneous 10

11 Pigment Network GLOBULES HOMOGENEOUS Step 2. Fit a Known Pattern? 11

12 Benign nevus patterns Marghoob A, et al. The Beauty and the Beast Sign in Dermoscopy. Derm Surg. Nov 2007 Nevus evolution Peripheral globules & Reticular Patchy reticular Central reticular network Yes Observe Yes Step 2. Fit a Benign Nevus Pattern? Does it Fit? Step 1: Melanocytic? pigment network, globules, homogeneous? No Yes Melanoma Biopsy/Excise Step 3. Are there Melanoma Features? No No Step 2. Structures seen in DF, BCC, SK, Angioma, SCC? Concerning: Excise or Short-term monitoring 12

13 Dermoscopy for the Scared, Bewildered, & Confused 67 M with this brown macule on the flank Is there a pigment network, globules, or homogeneous color? 13

14 Does it fit a benign pattern? 25yo medical student got his haircut for 3 rd year rotation and the barber noted: Is there a pigment network, globules, or homogeneous color? 14

15 Does it fit a benign pattern? Copyright restrictions may apply. Marghoob, A. A. et al. Arch Dermatol 2010;146: References Lee JB, Hirokawa D. Dermatoscopy: facts and controversies. Clinics in Dermatol. 2010;28: Dolianitis C, Kelly J, Wolfe R, Simposon P. Comparative performance of 4 dermoscopic algorithms by nonexperts for the diagnosis of melanocytic lesions. Arch Dermatol. 2005;141: Carrera C, Marchetti MA, Dusza SW, et al. Validity and reliablilty of dermoscopic criteria used to differentiate nevi from melanoma a web-based International Dermoscopy Society study. JAMA Dermatol 2016;152: Marghoob, AA, Malvehy J, Braun R, eds. An Atlas of Dermoscopy, 2nd Edition. 2013; CRC Press, Boca Raton, FL BasicDermatoscopy.blogspot.com Dermnetznz.org Dermoscopy CME. No images were changed; Kittler, H., Pehamberger, H., Wolff, K. & Binder, M. Diagnostic accuracy of dermoscopy. Lancet Oncol, 2002;3: Binder, M., Schwarz, M., Winkler, A., et al. Epiluminescence microscopy. A useful tool for the diagnosis of pigmented skin lesions for formally trained dermatologists. Arch Dermatol. 1995;131: Carli, P., de Giorgi, V., Chiarugi, A., et al. Addition of dermoscopy to con- ventional naked-eye examination in melanoma screening: a randomized study. J Am Acad Dermatol, 2004;50:683 9 Carli, P., De Giorgi, V., Crocetti, E., et al. Improvement of malignant/benign ratio in excised melanocytic lesions in the dermoscopy era : a retrospective study Br J Dermatol. 150,

16 Which of these is true about dermoscopy? Quick and minimally invasive Makes patients anxious Reduces unnecessary biopsies Which of these is true about dermoscopy? Quick and minimally invasive Makes patients anxious Reduces unnecessary biopsies Which dermoscopic method is better for visualizing structures in the dermis (deeper structures)? Non-polarized dermoscopes Polarized dermoscopes Both of these Neither of these 16

17 Which dermoscopic method is better for visualizing structures in the dermis (deeper structures)? Non-polarized dermoscopes Polarized dermoscopes Both of these Neither of these Which of these demonstrates melanocytic pigment globules? A B C Which of these demonstrates melanocytic pigment globules? A B C 17