​Dermatology - Acquired Nevomelanocytic Nevi (Moles)

​Dermatology - Acquired Nevomelanocytic Nevi (Moles)
Moles are prevalent skin abnormalities that are often tiny in size (<1 cm). They are well-defined and consist of pigmented macules, papules, or nodules formed by melanocytic nevus cells. These cells are found in the epidermis, dermis, and occasionally in the subcutaneous tissue. Although moles are mostly harmless, the likelihood of developing melanoma is associated with the quantity of moles present. Melanocytic nevi originate in the epidermis and migrate to the dermis, where they gradually diminish.

Moles are characterized by their lack of symptoms and are categorized as junctional, compound, or dermal melanocytic based on their location and stage of development. Junctional nevi originate at the boundary between the dermis and epidermis, compound melanocytic nevi penetrate into the dermis, and dermal melanocytic nevi are completely embedded within the dermis.

Functional moles manifest as circular or elliptical flat patches, or as minimally elevated little bumps.
Compound moles exhibit a dome-shaped appearance, occasionally with a surface resembling cobblestones. They may also be papillomous or hyperkeratotic. Dermal moles are round or dome-shaped papules or nodules that have a clear and distinct outline.
Junctional and compound moles exhibit a consistent coloration ranging from tan to black, with smooth and regular borders. They are distinct and spread out. Dermal moles exhibit a skin tone that is either similar to the surrounding skin, a tan color, or have specks of brown. Moles have a maximum diameter of 1 cm.

The diagnosis is primarily based on clinical examination, with the key objective being to exclude the presence of melanoma precursors and melanoma using the ABCDE criteria (asymmetric, irregular boundaries, mixed color, large diameter, and evolving). The differential diagnosis encompasses various skin conditions, such as solar lentigo, flat atypical nevus, lentigo maligna, other raised pigmented lesions, seborrheic keratosis, small superficial spreading melanoma, early nodular melanoma, pigmented basal cell carcinoma, dermatofibroma, Spitz nevus, blue nevus, neurofibroma, trichoepithelioma, dermatofibroma, and sebaceous hyperplasia.


Exclude melanoma precursors and melanoma, and if uncertain, employ dermoscopy, biopsy, or excision with a restricted margin.