Related Experiment Video
Updated: Mar 9, 2026
Author Spotlight: Anterior HR-OCT as a Non-Invasive Tool for Characterizing Ocular Surface Squamous Neoplasia
Published on: August 9, 2024
Recurrence of moderately dysplastic nevi with positive histologic margins
Bryan Hiscox1, Melissa R Hardin2, Ida F Orengo1
1Department of Dermatology, Baylor College of Medicine, Houston, Texas.
Background:
The Pigmented Lesion Subcommittee of the Melanoma Prevention Working Group recently published a consensus statement that incompletely excised moderately dysplastic nevi (MDN) without clinical residual pigmentation can be observed and not re-excised. However, data regarding recurrence of MDN with positive histologic margins are quite scant.
Objective:
We sought to extend the reported findings with a study to determine the recurrence rate of MDN with positive histologic margins.
Methods:
We performed a retrospective study on MDN with positive histologic margins that were not re-excised and for which at least 1 year of clinical follow-up was available.
Results:
We found a total of 147 such nevi from January 1, 2007, to December 31, 2013. Six MDN (5 compound and 1 junctional) or 4% recurred with an average recurrence time of 1.7 years. All of these MDN were evaluated by shave biopsies.
Limitations:
Subjectivity in grading of atypia is a limitation of this study.
Conclusion:
These data from a large study focusing exclusively on recurrence of MDN with positive histologic margins support the conclusion of the Pigmented Lesion Subcommittee that incompletely excised MDN do not require re-excision.
Insights
Incompletely excised moderately dysplastic nevi (MDN) with positive margins rarely recur. This study supports observing MDN without residual pigmentation, rather than re-excision, reducing unnecessary procedures.
Area of Science:
- Dermatology
- Pathology
- Oncology
Background:
- Consensus guidelines suggest observation for incompletely excised moderately dysplastic nevi (MDN) lacking residual pigmentation.
- Limited data exist on recurrence rates for MDN with positive histologic margins.
Purpose of the Study:
- To determine the recurrence rate of MDN with positive histologic margins.
- To provide evidence supporting current observational guidelines for MDN.
Main Methods:
- Retrospective study of 147 MDN with positive histologic margins.
- Cases were not re-excised and had at least one year of clinical follow-up.
Main Results:
- A low recurrence rate of 4% (6 out of 147 MDN) was observed.
- The average time to recurrence was 1.7 years.
- All recurrent MDN were initially evaluated by shave biopsy.
Conclusions:
- Data support the observation of incompletely excised MDN with positive margins.
- Re-excision may not be necessary for MDN lacking clinical residual pigmentation.
- Subjectivity in atypia grading is a study limitation.
