Severely Dysplastic Nevi: Should They Be Re-Excised to Prevent Melanoma?
Dysplastic nevus (DN) is the term used to describe nevi with cytologic atypia and architectural disorder. However, despite many attempts to develop guidelines for grading DN, studies have shown low reproducibility even among experienced dermatopathologists. This is particularly true for differentiating dysplastic nevi that show severe atypia from radial growth-phase melanoma.
Several different dermatology working groups and consensus statements advocate clinical observation for lesions with mild atypia and recommend removal of dysplastic nevi with severe atypia (SDN) when margins are involved after biopsy. Even though there are no formal guidelines that suggest best practices when margins are not involved, a majority of dermatologists perform re-excision when the pathology report mentions severe atypia, even when margins are clear. This practice has become more common because of the concern that these lesions may represent early melanoma.
A recent study sought to determine the rates of subsequent melanoma development in patients with SDN who underwent re-excision compared to those who did not, and to define factors associated with a decision to re-excise. The retrospective study looked at 451 patients with biopsy-proven SDN and at least 5 years of clinical follow-up. The results found 2 identified cases of melanoma upon re-excision of a SDN, representing 0.4% of all patients in the study, and 1.2% of patients who underwent re-excision of the original biopsy site. There were no cases of melanoma recurring at the same site in any patients who did not undergo re-excision. The authors note that an interesting finding was that most SDN in our series were not re-excised. They conclude that this is due to the retrospective nature of the study and state that a similar study conducted today might reflect that dermatologists are more likely to excise dysplastic nevi now than they were in the past. However, they conclude that based on their results and the results of other similar studies, routine re-excision of all SDN may not be necessary. Clinical observation, commonly used for mild-to-moderate dysplastic nevi, may be a safe treatment choice for SDN. They note that a prospective study could help clarify which lesions can safely be treated with clinical observation and could help to reduce the rates of re-excision of dysplastic nevi.
Byline: Martha L. Sikes, MS, RPh, PA-C
Posted: February 20, 2017
Adapted from the original article.