Dermoscopy patterns of halo nevi

Area of Science:

• Dermatology
• Dermoscopy
• Oncology

Background:

• Halo nevi (HN) are benign melanocytic nevi characterized by a surrounding depigmented halo.
• Understanding the dermoscopic features of HN and their evolution is crucial for accurate diagnosis.

Purpose of the Study:

• To evaluate the dermoscopic characteristics of halo nevi (HN).
• To assess changes in HN during digital dermoscopic follow-up.
• To determine the frequency of the halo phenomenon in melanomas.

Main Methods:

• Retrospective analysis of digital dermoscopic images of 138 HN in 87 patients.
• Classification of HN based on dermoscopic morphology.
• Evaluation of size changes in nevus and halo components over time.
• Review of 475 melanomas for the presence of halo-like depigmentation.

Main Results:

• Globular and/or homogeneous patterns were observed in over 80% of HN, typical for younger individuals.
• Follow-up of 33 HN showed significant size reduction of the nevus component without structural changes.
• Only 2 out of 475 melanomas exhibited a halo, and both had distinct melanoma-specific dermoscopic patterns.

Conclusions:

• Halo nevi display characteristic benign dermoscopic features, primarily globular or homogeneous patterns.
• Despite size fluctuations, the structural patterns of HN remain stable during follow-up.
• The presence of a halo in melanoma is rare and accompanied by specific dermoscopic criteria, rendering routine digital follow-up for HN diagnosis insignificant.