Dermatoscopy (synonyms: Reflected-light microscopy, reflected-light microscopy of the skin, epiluminescence microscopy) is a noninvasive and simple examination method in dermatology used especially for early detection of malignant (malignant) tumors of the skin. Asymmetry, blurred borders, variegated colorite, diameter greater than 5 mm or rapid growth, and elevation of the lesion are considered characteristics of melanoma.
Indications (areas of application)
- Skin cancer screening (skin cancer screening).
- Suspicion of a suspicious (suspicious) skin change.
The procedure
In dermoscopy, the skin is viewed with a microscope with the aid of oil and sometimes polarized light to deeper layers. Skin lesions, especially pigmented spots, can be magnified tenfold using a dermatoscope, allowing a more accurate diagnosis. In this way, benign and malignant changes can be distinguished. In the last 15 years, the number of new cases of malignant skin tumors in Europe has almost doubled. About 2-3 % of Germans are newly affected each year. About 1 % of cancer deaths are due to malignant melanoma.Malignant melanoma (black skin cancer) spreads rapidly. The early diagnosis of malignant skin changes is therefore urgently necessary in order to be able to initiate therapy measures in time.Whether a pigmented skin change can be benign (benign) or malignant (malignant) is determined with the help of the so-called ABCDE rule according to Stolz:
| A | Asymmetry |
| B | Limitation |
| C | “color variation” (inhomogeneous color) |
| D | Diameter |
| E | Sublimity/Evolution (Development) |
Asymmetry
If there is an irregularity in symmetry, this may be a sign of malignant (malignant) change: a spot that is not uniformly round or oval in shape is conspicuous
Boundary
Benign changes are usually sharply demarcated, whereas malignant tumors usually have blurred, fuzzy margins or extensions.
Color – Color
It is believed that the darker the skin change, the greater the suspicion of malignancy. Color variations within a pigmented patch can also be a sign of malignancy.
Diameter
Any pigmented spot larger than 5 mm should be closely observed.
Sublimity/Evolution (Development)
Elevation from the skin (> 1 mm), bumps, and nodules are not natural or E = evolution, i.e., has the lesion changed? Another rule is that of the “ugly duckling sign”. This is a lesion that looks completely different from all other lesions. Furthermore, differential structures are assessed by dermoscopy: these include vascular networks, “dots” (dark brown to black spots) or areas without structure, which can give the physician important information about the type of skin change. All these changes are difficult to see with the naked eye, so that a reliable diagnosis can only be made using a dermoscope.The findings are evaluated according to a point system. The higher the calculated value, the higher the suspicion of a malignant skin change.
Benefit
Early detection of malignant skin changes can help prevent the spread of the disease through timely therapy.At the same time, targeted differentiation between benign and malignant changes avoids unnecessary removal of benign skin changes. Skin cancer screening is available to everyone with statutory health insurance from the age of 35 every 2 years. This includes a visual (with the naked eye), standardized whole-body inspection (viewing) of the entire skin, including the hairy head and all body skin folds. Further notes
- According to an Internet-based study involving 130 examiners who had an average of approximately 12 years of dermatologic professional experience, the following criteria were found to be most strongly associated with the diagnosis of melanoma:
- Marked structural irregularity (OR 6.6).
- Pattern asymmetry (OR 4.9)
- Not organized pattern (OR 3.3)
- Rim score of 5 or 6 (OR 3.1 or 3.3, respectively).
- Asymmetry of contours (OR 3.2).
- Vascularization zones (new formation of small vessels) are also of diagnostic importance (viewing by dermatoscope with approximately 20x magnification):
- Malignant melanoma
- Initial stages of malignant melanoma (in situ melanoma): vascular dilatations (ectasias) due to inflammation or vascular neoplasms
- In later growth phases: mostly polymorphic, circumscribed or diffuse vascular patterns.
- Amelanotic and hypomelanotic lesions, respectively: characteristic vascular patterns (as a neoplastic reaction).
Most common neoplastic vascular patterns: vascularized cell nests, circumscribed and diffuse neovascularization/vascularization (circumscribed neovascularization already in in situ melanomas), peripherally accentuated vascularization, vascular dilatation (ectasia; in more pigmented melanomas signs of high malignancy/malignancy); furthermore, occurrence of combined or chaotic vascular patterns.
- Malignant melanoma
- Use of expert dermoscopy increases diagnostic accuracy for assessment of pigmented moles by 49% compared with clinical assessment alone (log-odds ratio 4.0 [95% CI 3.0-5.1] versus 2.7 [1.9 to 3.4]; improvement of 49%, p = 0.001)
