Section 09 of 09
Pulling It Together
Seborrhoeic keratosis is the lesion that dermoscopy was almost made for. Its features are distinctive, recognisable, and — when present — allow confident identification that spares patients unnecessary anxiety and referral.
The classic pattern rests on a few key pillars:
- Milia-like cysts — bright keratin pearls scattered across the surface
- Comedo-like openings — dark, plugged invaginations
- Fissures and ridges — the brain-like cerebriform surface
- Sharp demarcation — a well-defined border
- The wobble sign — gentle lateral movement confirming superficial position
But this module is equally about knowing the limits of that confidence. Variants — flat, irritated, clonal — may show fewer classic features. Mimickers — melanoma, pigmented BCC — can superficially resemble seb K. And the clinical context — rapid change, immunosuppression, the ugly duckling — can override dermoscopic reassurance.
The practical rule is simple: when the classic features are clearly present across the entire lesion and the clinical context is consistent, seborrhoeic keratosis can be identified with confidence. When anything does not fit — a suspicious area, an absent feature, a concerning history — treat it as uncertain and act accordingly.
| Feature | What to look for | Confidence level |
|---|---|---|
| Milia-like cysts | Bright white-yellow dots (keratin pearls) | High when multiple present |
| Comedo-like openings | Dark round plugged openings | High when combined with cysts |
| Fissures and ridges | Brain-like cerebriform surface | Supportive (absent in flat variants) |
| Sharp demarcation | Well-defined, crisp border | Supportive |
| Wobble sign | Lateral movement under dermatoscope | Supplementary |
| Moth-eaten border | Concave, scalloped edge | Supportive |
What comes next
You have now learned to recognise the first of the three key benign lesion patterns that form the foundation of the TADA algorithm. Module 5 covers cherry angioma — a vascular lesion with an equally distinctive dermoscopic fingerprint — and Module 6 tackles dermatofibroma. Together, these three modules give you the benign pattern recognition skills that TADA's first step depends on.
An older patient presents with a well-demarcated dark brown lesion on their trunk. You see multiple milia-like cysts and comedo-like openings across most of the lesion, but one area at the edge shows a blue-grey colour with no cysts or openings. What is the most appropriate next step?
This module teaches dermoscopic pattern recognition for educational purposes. It does not provide clinical recommendations. In real practice, always follow your local clinical guidelines and referral pathways.