Borderline pigment nevus is a pigmented nodule up to 1 cm in size, the color of which can vary from light brown and gray to black. Borderline nevus can have any localization. It is more often a single one. Diagnosis is carried out by dermatological examination, dermatoscopy, syascopy. In order to prevent melanoma, removal of the nevus by laser, radio wave apparatus, liquid nitrogen, electrocoagulation or by surgical excision is recommended. If necessary, a histological examination of the removed material is performed.
Borderline pigmented nevus is most often a congenital neoplasm. Less often it appears in childhood, puberty or later. Along with Ota nevus, blue nevus, Dubreuil melanosis and giant pigment nevus, borderline pigment nevus can undergo malignant degeneration. Therefore, dermatology refers it to melanoma-threatening nevi.
Borderline pigment nevus is a flattened nodule of gray, black, light or dark brown color. Its dimensions range from a few millimeters to 4-5 cm, but more often do not exceed 1 cm. The surface of the nevus is smooth and dry, may be slightly uneven. A distinctive feature is the absence of hair growth (even fluffy) on the surface of the nevus. Borderline nevus does not have a favorite localization and can be located on any part of the body, including on the palms and soles, where other types of nevi are practically not found. Usually the borderline nevus is a single formation, but there are cases of multiple nevus.
A kind of border nevus is a cockade nevus, characterized by a gradual increase in pigmentation along the periphery of the formation, due to which, over time, the nevus takes the form of concentric rings, differing in different color saturation. A change in the color of the border pigment nevus, its sharp increase, the appearance of cracks, erosions or bumps on its surface, the appearance of redness around the nevus or the vagueness of its borders may indicate a malignant transformation and require urgent consultation with a dermatologist.
Borderline pigmented nevus is diagnosed during dermatological examination and dermatoscopy. An additional method is siascopy. If a malignancy of the nevus is suspected, a consultation with a dermatooncologist is required.
A skin biopsy from the borderline pigmented nevus is usually not performed, since such an injury can give an impetus to its malignant degeneration. Histological examination is carried out after removal of the nevus by surgical or radio wave method.
Borderline pigment nevus is differentiated from other pigment formations: freckles, pigment spots, Setton nevus, Dubreuil melanosis, blue nevus.
Patients with borderline pigmented nevus are recommended to be monitored by a dermatologist. As a benign neoplasm of the skin, it does not need urgent removal. But it should be remembered that borderline pigmented nevus refers to melanoma-threatening and the best way to prevent melanoma is to remove the nevus. The indication for surgical treatment of nevus is its constant traumatization, especially when located on the soles or palms.
Removal of the borderline pigment nevus can be carried out with a surgical scalpel, laser or radio wave apparatus. Electrocoagulation and cryodestruction of the nevus is not desirable, since according to some experts, these removal methods cause severe tissue injury, which can lead to the development of melanoma at the site of the removed pigment nevus.
Laser removal of moles does not leave behind a cosmetic defect. However, it can only be used in cases where histological examination of the removed material is not required. Removal of nevi with a radiosurgical knife is more often carried out with their sizes up to 5 mm. Both methods do not require suturing with small sizes of formation. If signs of malignant transformation of the nevus are detected, its urgent surgical excision is performed, followed by histological examination of the removed material.