Modern Dermoscopy.

How to choose between gestalt pattern analysis, the revised seven-point checklist, the ABCD rule, the Menzies method, and the comparative ugly-duckling approach in real practice.

Triage, monitoring, biopsy thresholds, and patient self-monitoring rules that turn dermoscopic findings into defensible clinical actions.

Ten dermoscopic nevus patterns linked to age, anatomic site, and growth phase, used to identify the lesion that breaks the patient's predominant pattern.

Symmetric starburst, globular, or homogeneous patterns define benign Spitz and Reed nevi, while asymmetric variants in adults raise the spectrum of atypical Spitz tumors and spitzoid melanoma now stratified by kinase-fusion biology.

Homogeneous structureless blue defines common blue nevus, while combined nevi, deep penetrating nevi, and rare malignant blue nevus extend the dermal melanocytic spectrum into territories that overlap with nodular melanoma.

Size-based classification (small, medium, large, giant) drives melanoma risk estimation and neurocutaneous melanocytosis screening, while dermoscopy reveals globular, reticular, mixed, and structureless patterns with characteristic cobblestone surface and hypertrichosis.

Multicomponent asymmetric architecture, atypical network, blue-white veil, regression, and atypical vessels define the dermoscopic vocabulary of cutaneous melanoma.

Facial chronically sun-damaged skin produces lentigo maligna with follicle-centered features (asymmetric pigmented follicles, gray circles, rhomboidal structures) that progress through a defined four-stage model, requiring an inverse-approach diagnostic strategy and staged surgical mapping.

Parallel ridge pattern is the dermoscopic hallmark, but up to half of acral melanomas lack it; the BRAAFF checklist combines six features to deliver 93% sensitivity and 87% specificity.

Nodular, amelanotic/hypomelanotic, and spitzoid melanomas escape the SSM dermoscopic vocabulary, requiring vessel-driven, color-based, and age-stratified diagnostic strategies.

UV-driven intraepidermal dysplasia on the in-situ end of the keratinocyte cancer spectrum, recognized dermoscopically by the strawberry pattern, white circles, and rosettes.

Full-thickness epidermal atypia recognized dermoscopically by clustered glomerular and dotted vessels on a salmon-pink background with surface scale.

The keratin-producing end of invasive SCC, defined dermoscopically by central keratin masses, white circles around follicles, white halos around vessels, and hairpin vessels.

The aggressive end of cutaneous SCC, defined by NCCN 2025 risk criteria, recognized dermoscopically by red-dominant polymorphous vessels and bleeding, and now actionable through molecular risk stratification (40-GEP) and immunotherapy.

Mucosal in-situ SCC of the penis. HPV-driven and HPV-independent pathways with distinct clinical and dermoscopic signatures.

Inflammatory and benign neoplastic conditions that mimic SCC dermoscopically (irritated seborrheic keratosis, erosive pustular dermatosis of the scalp, hypertrophic lupus, Bowenoid papulosis, lichen planus mimics, eccrine poroma) and how to distinguish them.

BCC is the most common human cancer; dermoscopy raises sensitivity to 91 to 99 percent and lets the clinician predict subtype before biopsy.

The pearly papule with sharp arborizing telangiectasias; recognize it on the face and treat with excision or Mohs depending on risk.

The flat pink trunk plaque with short fine telangiectasias and small erosions; the only BCC subtype where topical therapy is first-line.

Pigmented variants follow Menzies criteria, but the differential against melanoma is the entire reason dermoscopy was invented.

The scar that is not a scar: poorly demarcated white plaques with subtle vessels on photodamaged skin demand Mohs and RCM-guided margin mapping.

A rapidly expanding red-pink nodule on sun-damaged skin of an older or immunosuppressed patient; nonspecific dermoscopy but high mortality drives early biopsy.

A rapidly enlarging red-pink dome on the bald scalp or forehead of an elderly fair-skinned patient; AFX and PDS sit on a continuum defined by depth, vascular and perineural invasion.

A slowly enlarging pink-to-violaceous plaque or nodule on the trunk or shoulder of a young to middle-aged adult, defined by COL1A1-PDGFB fusion and treated with margin-controlled surgery.

A vascular neoplasm caused by HHV-8 with a characteristic dermoscopic rainbow pattern of multicolored homogeneous areas, occurring in classic, endemic, iatrogenic, and HIV-associated forms.

Mycosis fungoides shows orange-yellow structureless areas, fine scale, and the spermatozoa-like (J-shaped) vessels that distinguish early MF from chronic dermatitis on dermoscopy.

The most common benign tumor in clinical practice, defined dermoscopically by milia-like cysts, comedo-like openings, fissures, and hairpin vessels with white halos.

A central white scar-like patch surrounded by a delicate peripheral pigment network defines classic dermatofibroma, with a growing list of atypical variants demanding histopathologic confirmation.

Red, blue, and purple lacunae, white septae, ulceration with collarette, and characteristic vascular morphologies define a broad spectrum of benign vascular lesions and the dermoscopic differential against amelanotic melanoma and Kaposi sarcoma.

Vessel morphology, vessel distribution, scale color, and background color resolve the four-way fork between psoriasis, eczema, lichen planus, and pityriasis rosea at the chair side.

Orange-yellow background plus linear vessels signals granulomas; perifollicular plugs plus telangiectasias signal interface autoimmunity; sclerotic white-yellow plus comedo-like openings signals lichen sclerosus or morphea.

The delta-wing jet with contrail of scabies, the comma and corkscrew hairs of tinea capitis, the central pore with crown vessels of molluscum, and the frog-eye papillae of warts; entodermoscopy turns the dermatoscope into a non-invasive microscope for skin parasites and infections.

Spermatozoa-like (J-shaped) vessels and orange-yellow structureless areas separate early patch-stage mycosis fungoides from chronic dermatitis and parapsoriasis on the dermatoscope.

Longitudinal melanonychia stratification + the unpigmented nail-unit tumor algorithm, without these, nail biopsy is a guessing game.

Furrow vs ridge, one rule that triages 95% of acral pigmented lesions.

On the glabrous mucosa, parallel patterns are benign and multicomponent disorganized patterns suggest melanoma; LSA, VIN, and Paget have their own dermoscopic signatures.

Yellow dots, vellus, peripilar signs, the trichoscopic toolkit for AGA, alopecia areata, scarring alopecia and the LPP/FFA spectrum.

Trichoscopy of the scarring alopecias: peripilar grey-white halos, follicular keratin plugs, follicular red dots, tufted hairs, and pinpoint white dots map to histology and guide management.