From the Guidelines
Benign acral junctional nevi are harmless moles that do not require treatment, but regular monitoring is essential to detect any changes that may suggest malignant transformation, as recommended by the most recent guidelines 1. These pigmented lesions are characterized by melanocytes clustered at the junction between the epidermis and dermis, and are commonly found on the palms, soles, fingers, or toes. The key features to monitor include:
- Asymmetry
- Border irregularity
- Color variation
- Diameter >6mm
- Evolution, as outlined in the ABCDE rule, which can help identify potentially malignant lesions 1. Regular self-examination and annual skin checks by a dermatologist are advisable, particularly for individuals with multiple nevi or risk factors for skin cancer, to ensure early detection and treatment of any potential malignancies 1. It is essential to distinguish benign acral junctional nevi from acral melanoma, especially in darker-skinned individuals where acral melanoma is more common, and a skin biopsy may be necessary to confirm the diagnosis if there are concerning features 1. Dermoscopy by an experienced physician can also enhance the diagnostic accuracy, and an automated video-dermoscopy system can provide improved diagnostic accuracy for patients with multiple atypical naevi in the follow-up 1. The histology report should follow the American Joint Committee on Cancer (AJCC) classification, and include information on the maximum thickness, mitotic rate, presence of ulceration, and clearance of the surgical margins, as well as the melanoma type and anatomical site 1. Mutation testing for treatable mutations is mandatory in patients with advanced disease, and should be carried out in accredited institutes with careful quality controls 1.
From the Research
Benign Acral Junctional Nevi
- Benign acral junctional nevi are a type of melanocytic nevus that can be found on the acral skin, which is the skin on the palms of the hands and soles of the feet 2, 3.
- These nevi are typically benign, but they can be difficult to distinguish from acral lentiginous melanoma, a type of skin cancer that is more common in non-Caucasian populations 4, 2.
- Dermoscopy, a non-invasive technique that uses a special microscope to examine the skin, can be helpful in differentiating between benign acral junctional nevi and acral lentiginous melanoma 4, 3.
- The dermoscopic pattern of benign acral junctional nevi is typically characterized by pigmentation along the furrows of the skin markings, whereas acral lentiginous melanoma typically shows pigmentation on the ridges of the surface skin markings 3.
Diagnosis and Management
- The diagnosis of benign acral junctional nevi is typically made based on a combination of clinical and dermoscopic findings, as well as histopathologic examination of a biopsy specimen 2, 3.
- The management of benign acral junctional nevi usually involves observation and monitoring for any changes in size, shape, or color, as well as regular skin checks to detect any new or suspicious lesions 4, 3.
- In some cases, surgical excision may be necessary to confirm the diagnosis or to remove a suspicious lesion 5, 6.
- The use of lasers, such as Q-switched or normal mode pigment lasers, may also be effective in treating benign acral junctional nevi 5.
Differential Diagnosis
- The differential diagnosis of benign acral junctional nevi includes acral lentiginous melanoma, as well as other types of pigmented lesions such as acral melanosis and non-melanocytic pigmented lesions 4, 2.
- A thorough clinical and dermoscopic examination, as well as histopathologic examination of a biopsy specimen, is necessary to distinguish between these different conditions 4, 2, 3.