Dysplastic nevushttps://en.wikipedia.org/wiki/Dysplastic_nevus
Dysplastic nevus is a nevus whose appearance is different from that of common nevi. Dysplastic nevi often grow to be larger than ordinary nevi and may have irregular and indistinct borders. Dysplastic nevi can be found anywhere, but are most common on the trunk in men, and on the posterior side of the lower leg in women.

Cancer risk
As seen in Caucasian individuals in the United States, those with dysplastic nevi have a lifetime risk of developing melanoma of greater than 10%. On the other hand, those without any dysplastic nevus have a risk of developing melanoma of less than 1%.

Precaution for individuals with dysplastic nevi
Skin self-examination is usually recommended for preventing melanoma (by identifying atypical nevi that can be removed) or for early detection of existing tumors. People with a personal or family history of skin cancer or of multiple atypical nevi should see a dermatologist at least once a year to be sure they are not developing melanoma.

The abbreviation [ABCDE] has been useful for helping health care providers and laypersons remember the key characteristics of a melanoma. Unfortunately for the average person, many seborrheic keratoses, some lentigo senilis, and even warts may have [ABCDE] characteristics, and cannot be distinguished from a melanoma.

Asymmetrical: Asymmetrical skin lesion.
Border: The border of the lesion is irregular.
Color: melanomas usually have multiple irregular colors.
Diameter: nevi greater than 6 mm are more likely to be melanomas than smaller nevi.
Evolution: The evolution (i.e. change) of a nevus or lesion may indicate that the lesion is becoming malignant.

  • Dysplastic nevi ― Biopsy is recommended for Westerners.
  • An asymmetric shape with a blurry lesion margin indicates a possible Dysplastic nevus. But the color and size are relatively within a normal range. A biopsy is necessary for confirmation.
  • Irregular shape matches the criteria of the ABCD rule (asymmetry), but the decision may vary among evaluators.