Moles

A mole is a focal proliferation of melanocytes - the cells responsible for producing melanin, the pigment that gives color to the skin, hair, and irises. In healthy skin, melanocytes are evenly distributed in the basal layer of the epidermis. In moles, they cluster together in the form of cellular nests.

From a histopathological perspective, there are three main locations of melanocytes within the skin:

• Junctional nevi - cells located at the junction of the epidermis and the dermis.
• Dermal nevi - melanocytes present exclusively in the dermis.
• Compound nevi - involving both of the above layers.

Typical clinical features of a benign mole include:

• Symmetrical shape,
• Uniform color (brown, light brown, beige),
• Smooth, distinct borders,
• Usually a diameter of <6 mm,
• Stability over time.

The assessment of moles should be conducted according to the **ABCDE** rule (Asymmetry, Border, Color, Diameter, Evolution), which helps in the early detection of features that may suggest the development of melanoma.

Pigmented nevi are classified based on clinical criteria, histological criteria, and the time of appearance.

1. Based on the time of formation:

• Congenital nevi – present from birth; they can be small, medium, or giant. Large congenital nevi are associated with an increased risk of melanoma development.
• Acquired nevi – appear during childhood and youth; their number increases under the influence of UV.

2. Based on clinical appearance:

• Typical pigmented nevi – regular, symmetrical.
• Atypical (dysplastic) nevi – irregular, with uneven pigmentation, often >6 mm; require special observation.
• Spitz nevus – usually pink or reddish, more common in children; may clinically resemble melanoma.
• Blue nevus – bluish, resulting from the deep location of melanocytes in the dermis.

3. Lesions mimicking moles:

Not every pigmented lesion is a melanocytic nevus. Differentiation includes, among others:

• seborrheic keratoses,
• soft fibromas,
• hemangiomas,
• actinic keratosis,
• malignant melanoma.

Every new, rapidly growing, or changing skin lesion requires dermatological diagnosis, preferably using digital dermoscopy or videodermoscopy.

Removal of moles is recommended in several situations:

• suspected malignant transformation,
• presence of atypical features in dermoscopic examination,
• mechanical irritation (e.g., by clothing),
• aesthetic reasons,
• injury to the lesion.

The primary and recommended method for removing pigmented lesions is surgical excision with a margin of healthy tissue, with mandatory histopathological examination. This is the only method that allows for full microscopic evaluation and exclusion of melanoma.

In selected cases of benign lesions, other techniques are also possible:

• laser therapy (CO₂ laser) – mainly used for lesions with confirmed benign nature,
• radiosurgery (radio wave) – precise removal of small skin lesions,
• electrocoagulation – less commonly used for pigmented lesions.

In clinical practice, it is crucial that every pigmented lesion intended for removal is previously evaluated dermoscopically by a physician. Removing moles without prior diagnostics increases the risk of missing an early stage of melanoma.

In a modern dermatological clinic, the following are performed:

• manual and digital dermoscopy,
• surgical excision of skin lesions with histopathological examination,
• removal of selected benign lesions using laser or radiosurgical methods.

Regular monitoring of moles (once a year, and more frequently for those at risk) is a fundamental element of melanoma prevention.