Chaos and clues
|Description||This chapter describes the chaos and cluesThis glossary term has not yet been described.This an algorithm used in dermoscopy [[Chaos and Clues]] approach|
|Responsible author||Harald Kittler → send e-mail|
|Status update||January 17, 2019|
|Status by||Ralph P. Braun|
- It is designed to be applied to any pigmented skin lesion to rapidly detect any type of malignancy, or to guide the clinician in the decision whether a lesion should be excised or biopsied rather than to make a specific diagnosisis the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines with variations in the use of logic, analytics, and experience to determine "cause and effect". In systems engineering and computer science, it is typically used to determine the causes of symptoms, mitigations, and solutions.
- The clinical and dermatoscopical examination for chaos is being defined as asymmetry of structure or colorColor (American English) or colour (Commonwealth English) is the characteristic of human visual perception described through color categories, with names such as red, yellow, purple, or blue..
- When chaos is discovered, the lesion is being searched for one of eight cluesEvidence, in an investigation to malignancy.
- If there are both chaos and at least one clue to malignancy then biopsy is indicated.
- Definition: asymmetry produced by the pattern of structuresThis glossary term has not yet been described. or colorsThis glossary term has not yet been described. within a lesion.
- Any color other than skin color at the edge of a lesion (such as white) should be regarded as part of the lesion.
- A lesion with one pattern and one color, regardless of its shape, is symmetrical and therefore does not exhibit chaos. If any line drawn through the center of a lesion has different colors or structures on opposite sides it is asymmetrical and exhibits chaos.
- Lesions without chaos are not analyzed any further.
- It is very rare to find perfect symmetry in nature. If a decision cannot be made the lesion should be assessed as exhibiting chaos.
- Definition: a feature which indicates that a lesion requires a biopsy to exclude malignancy. One clue is sufficient.
- There are eight clues to pigmented malignancy (melanomaThis glossary term has not yet been described., pigmented basal cell carcinomaThis glossary term has not yet been described. (pBCC), and pigmented Bowenalso known as squamous cell carcinoma in situ is a neoplastic skin disease. It can be considered as an early stage or intraepidermal form of squamous cell carcinoma. It was named after John T. Bowen’s diseaseThis glossary term has not yet been described. (pBD).
- Eccentric structureless areahomogenous pattern various diagnoses: any color except skin color.
- Gray or blue structures: Gray dots may be seen in pBCC and pBD as well as melanoma. Gray circles occur in noninvasive facial melanomas.
- Black dots or clodsThis glossary term has not yet been described., peripheral: They are generally produced by melanoma cells or nests, respectively.
- Lines radial or pseudopodsBulbous and often kinked projections seen at the lesion edge, either directly associated with a network or solid tumor border., segmental: Lines radial may be seen at any location in BCCAbbreviation for Basal Cell Carcinoma. Pseudopods or lines radial when circumferential area feature of Reed nevusThis glossary term has not yet been described., but if segmental they are highly specific for melanoma.
- Polymorphous vesselsmultiple types of vessels are present may indicate malignancy in appropriate context for example in flat melanocytic lesions: VesselsThis glossary term has not yet been described. are called polymorphous when more than one pattern of vessel is seen. They reflect disordered malignant growth pattern and possibly increased metabolic demand of actively growing tumorThis glossary term has not yet been described. tissue.
- White linesstreaksThis glossary term has not yet been described.: To qualify as a clue, they must be clearly lighter than perilesional skinThis glossary term has not yet been described..
- Lines reticular or branched, thick: To be called thick, the lines must be thicker than the spaces they surround. They are produced by melanoma cells.
- Lines parallel, ridges (acral skin): Clue to malignancy even in the absence of chaos. Subcorneal hemorrhage also produces this pattern.