Derm SCE

Dermoscopy in the SCE: the patterns you cannot afford to miss

A practical guide to the dermoscopy patterns tested most often in the Dermatology SCE: melanocytic versus non-melanocytic, vascular clues, the classic traps, and the fastest way to build pattern recognition before exam day.

Editorial illustration of a dermatoscope examining a skin lesion with pattern overlays

Dermoscopy turns up in every Dermatology SCE paper, and it is not optional. The good news is the exam does not expect expert fluency. It tests the same defined set of patterns over and over, and candidates who have drilled those patterns score well on what everyone else finds intimidating.

Step 1: is it melanocytic?

A lesion counts as melanocytic if it shows any of these: a pigment network, aggregated globules, homogeneous blue pigmentation, or a parallel pattern on acral or mucosal sites. If none are present, switch to the non-melanocytic criteria.

  • Pigment network. A reticular grid of lines over the follicular openings. A regular mesh suggests benign; an irregular, thickened network that ends abruptly should raise suspicion.
  • Aggregated globules. Round, regular, same-size blobs point to a benign compound naevus.
  • Homogeneous blue. A blue naevus, or, alongside other features, melanoma.
  • Parallel pattern on acral skin. The furrow pattern is benign; the ridge pattern is acral lentiginous melanoma until proven otherwise.

Malignant melanocytic features to know cold

  • Atypical pigment network. Irregular meshwork, unevenly thickened, ending abruptly at the edge.
  • Blue-white veil. An irregular, structureless blue-white area over raised pigment. Highly specific for melanoma.
  • Regression structures. White scar-like areas and fine grey peppering, a sign of spontaneous tumour regression.
  • Irregular streaks. Radial lines at the edge that vary in size and spacing.
  • Irregular dots and blobs. Black or brown dots scattered asymmetrically, away from the follicular openings.
  • Multicomponent pattern. Three or more distinct zones in one lesion. Highly specific for melanoma.
Illustration of dermoscopy image practice on a laptop and phone
Image-based question practice is the quickest route to recognition under exam conditions.

Non-melanocytic patterns: BCC, SCC and seborrhoeic keratosis

  • BCC. Arborising (branching, bright-red) vessels, blue-grey ovoid nests, leaf-like structures at the edge and no pigment network. Look for shiny white structures on polarised dermoscopy.
  • SCC. White circles and rosettes on polarised light, hairpin or looped vessels, white structureless keratin areas and surface scale.
  • Seborrhoeic keratosis. Milia-like cysts, comedo-like openings, fingerprint-like structures on flat lesions, a sharp stuck-on border and fat fingers or ridges.

Vascular patterns at a glance

  • Dotted, regular. A benign melanocytic naevus, especially in children.
  • Dotted, irregular. Melanoma.
  • Arborising (branching). BCC.
  • Hairpin or looped. A keratinising lesion such as SCC or an irritated seborrhoeic keratosis.
  • Polymorphous (mixed). Melanoma or SCC.
  • Glomerular (clustered, convoluted). Bowen's disease.

The traps that catch people out

  • Facial lesions. There is no typical pigment network on facial skin because the follicles disrupt it, so rely on grey structures, the annular-granular pattern and asymmetric follicular openings.
  • Acral lesions. The furrow (benign) versus ridge (melanoma) distinction is asked again and again, so do not muddle them.
  • Nail unit. Hutchinson's sign, and the micro-Hutchinson sign seen only on dermoscopy, point to subungual melanoma.
  • Scalp. Yellow dots, black dots and broken hairs in alopecia areata are a recurring image question.
  • Pink or amelanotic lesions. With no pigment to go on, work entirely from the vascular pattern.

Building fluency before the exam

  • Image-based questions are the fastest route to recognition under pressure. Favour banks that pair clinical and dermoscopy images with worked explanations.
  • DermNet and the ISIC Atlas give you free, high-volume image collections to drill.
  • The BAD dermoscopy e-learning module is concise and free for members.
  • Spaced repetition with image cards, pairing each pattern with its diagnosis and reviewing at growing intervals.

Sources & further reading

For educational use only. Check current official guidance.

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