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.

○ [ABCDE]
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.
References Dysplastic Nevi 29489189 
NIH
A dysplastic nevus is also referred to as an atypical or Clarks nevus and has been the topic of much debate in the fields of dermatology and dermatopathology. It is an acquired mole demonstrating a unique clinical and histopathologic appearance that sets it apart from the common nevus. These moles appear atypical clinically, often with a fried-egg appearance, and are commonly biopsied by providers due to the concern for melanoma.
 Publication Trends and Hot Topics in Dysplastic Nevus Research: A 30-Year Bibliometric Analysis 37992349 
NIH
Dysplastic nevus, also called atypical or Clark nevus, can be precursor to melanoma, as the observation that 36% of melanomas have dysplastic nevi near the invasive tumor supports. Signs that a dysplastic nevus may have transitioned into a melanoma include asymmetry in contour, a noticeable increase in pigment variations, or a grayish tint indicating regression. These malignancies typically arise at a younger age (mid-thirties), are sometimes multiple, and are often found on the trunk. Molecularly, dysplastic nevi have a profile intermediate between benign nevi and malignant melanoma. While there is a recognized connection between dysplastic nevi and melanoma, it’s crucial to note that only about 20% to 30% of melanomas evolve from preexisting nevi. Given that the majority of dysplastic and typical nevi do not develop into melanoma, preventive removal of melanocytic nevi is not typically advised.
 Malignant Melanoma 29262210 
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A melanoma is a tumor produced by the malignant transformation of melanocytes. Melanocytes are derived from the neural crest; consequently, melanomas, although they usually occur on the skin, can arise in other locations where neural crest cells migrate, such as the gastrointestinal tract and brain. The five-year relative survival rate for patients with stage 0 melanoma is 97%, compared with about 10% for those with stage IV disease.