Dermoscopy in everyday practice Trilokraj Tejasvi MD Assistant Professor, Department of Dermatology, Director Teledermatology services, University of Michigan, Faculty Associate, GLOBAL REACH, Michigan Medicine Staff Physician, Physician Champion Teledermatology (VISN11) and Lead Teledermatology reader, Dermatology Service, Ann Arbor Veteran Affairs Hospital. What and Why? The analysis of primary morphology of microscopic subsurface skin structures that are not visible to the unaided eye. Link between macroscopic clinical dermatology and microscopic dermatopathology. Doctor- Stethoscope : Dermatologist Dermoscope. When in doubt cut it out? When in doubt check it out! with a dermatoscope. What happens when you don t doubt? 1
NPD vs. PD PD NPD Liquid interface Non-polarized dermoscopy (NPD) For most applications, 70% alcohol is recommended - yields fewer air bubbles and clearer images -hygienic reduces bacterial contamination. For examination of the nail apparatus gels are superior - The gels viscosity prevents it from rolling off the convex nail surface. - Purell gel Polarized dermoscopy (PD) Utilizes 2 filters to cancel out any light reflected off the surface of the stratum corneum ( and superficial light) 2
Wild,Wild West with DL4! Dermlite 4 (DL4) Hybrid scope 30mm lens 3 buttons (stand alone on/off, toggle between NP and P, and Pigment boost and orange light) 3
Toggle button* Power indicator Pigment Boost/orange light On/Off * Default polarized light Toggle button* Power indicator * Default polarized light Steps to use Dermoscope Use Alcohol pad to wipe the area of visualization. Start with Non contact mode. (non-contact polarized) Then use the Contact mode * (polarized followed by non-polarized) Also wipe the contact surface with fresh alcohol pad before and after you use the dermoscope. 4
Differences between dermatoscopes Polarized Both contact and noncontact No need for liquid immersion fluid Small pocket size New devices Non- polarized Requires contact with skin Requires liquid immersion Larger size Most of the images seen in atlases and lectures are taken using these scopes Differences between dermatoscopes Polarized Deeper structures Altered collagen- Crystalline structures or sign Vessels (especially with NCP) Non-polarized Epidermal features are more prominent (ridges, milia-like cysts, comedo-like openings) Regression structures (gray dots /granules) are better seen Blue white veil is more prominent NP PC PNC 5
NP PC PNC NP PC PNC NP PC PNC 6
NP PC PNC Colors in dermoscopy Colors play an important role in dermoscopy. Common colors are light brown, dark brown, black, blue, blue-gray, red, yellow, and white. The most important chromophore in melanocytic neoplasms is melanin 7
What is the bottom line? Biopsy or No Biopsy! CHAOS AND CLUES 8
Line: two dimensional continuous object with length greatly extending the width Pseudopod: a line with bulbous end Circle: a curved line equidistant from a central point Clod: any well circumscribed, solid object larger than a dot; clods can take any shape Dot: an object too small to have a discernable shape Reticular Branched Parallel Radial Curved Dots Clods Lines Looped Curved Serpentine Helical Coiled 9
Arrangement Random Clustered Serpiginous Linear Centered Radial Reticular Branched What is Chaos? Asymmetry of structure or color Eight Clues of Malignancy 1. Eccentric structure less area 2. Thick lines reticular or branched 3. Grey or blue structures 4. Peripheral black dots or clods 5. Lines radial or pesudopods, segmental 6. White lines 7. Polymorphous vessels 8. Lines parallel ridge (acral) or chaotic (nails) 10
Exceptions! Changing lesion in a adult Nodular pigmented lesions Dermoscopic grey structures on head and neck Parallel ridge pattern on palms and soles For Non-melanocytic lesions 2 STEP ALGORITHM 11
SCC and Keratoacanthoma White circles - most specific for SCC Keratin Vessels linear and dotted vessels Blood spots 12
Basal Cell Carcinoma Pigmented BCC Absence of pigment network Linear and arborizing (branch-like) telangiectasia Structure less or leaf-like areas on the periphery of the lesion Large blue-grey ovoid nests or blotches Multiple blue-grey globules Specks of brown and grey pigment Spoke wheel areas (radial projections from a well circumscribed dark central hub) Focal ulceration Chrysalis polarized only Non pigmented BCC Superficial BCCs -bluish-pink color, asymmetrical arborizing vessels and focal ulceration. Slight scaling and white areas of regression may also be present. Nodular basal cell carcinomas lose the blue hue and instead have a white rim around central ulceration. Milia may be present Milia like cysts Milia-like cysts are round white or yellow lesions due to intraepidermal keratin. They are characteristically found within a seborrhoeic keratosis. They may also arise within dermal melanocytic naevi, basal cell carcinoma and melanoma. 13
Fissures and Comedo like openings Comedo-like openings are sometimes called crypts. They are little craters and tend to be dark brown, like irregular globules. They are often associated with fissures (clefts). They are characteristic of seborrhoeic keratoses, but may also be found in dermal nevi. Rarely, they may be found in melanoma Cerebrifrom structures A seborrheic keratosis may have a cerebriform or brain-like pattern. The pattern is composed of fissures and ridges mimicking the gyri and sulci of the brain. This is a useful sign in the absence of comedo-like openings or milia-like cysts. Finger print like structures These are a descriptive term for tan or dark-brown, fine parallel cord-like structures characteristically seen in seborrhoeic keratoses and solar lentigo. Wider cords are called fat fingers. Fat fingers are also rarely seen in melanoma. 14
Dermoscopy of Facial lesions Facial skin is characterized by its flat dermalepidermal junction Early presence of solar elastosis in its dermis A thinner epidermis allows better visibility of dermal structures such as blood vessels or melanophages (usually reflecting the presence of histopathologic features of regression). Face-specific dermoscopic features are due to the relatively larger pilo-sebaceous units present in facial skin, interrupting the pigmentation by the creation of a broader network with round-shaped holes Nevi on the face Characterized by the presence of brown globules, comma-like vessels, and in some cases the presence of orange-colored superficial keratin Second group is characterized by a globular (or cobblestone) pattern, the presence of a positive wobble sign and, in some cases, a squamous surface Both types of lesion are usually dermoscopically homogeneous and geometrically symmetric. Features of concern Annular granular pattern Different vascular pattern (compared to the vascularity of the surrounding skin) Red rhombodial structures O, C and signet ring shaped structures Pigmented rhomboidal structures 15
Acral skin Acral skin is defined by its presence distal of the Wallace line (that separates the glabrous skin of the limbs from the skin beyond) It is characterized by the presence of dermatoglyphs Dermatoglyphs are constituted by the parallel arrangement of ridges and furrows Dermoscopic patterns observed on acral skin are mainly characterized by their position along the ridges and furrows, creating parallel pigmentation patterns and their variants Dermoscopic examination of the area of the junction between acral and glabrous skin of the limbs shows so-called transitional patterns, which are very difficult to analyze Acral skin Furrow ink test 16
Parallel pigmentation pattern Mucosal lesion Diameter larger than 1 cm, gray color, and the presence of structureless areas are highly suggestive for mucosal melanoma. Only 1 color and regular dermoscopic structures are the main criteria of mucosal melanosis. 17