Surgical re‐excision vs. observation for histologically dysplastic naevi: a systematic review of associated clinical outcomes

Summary Background The management of histologically dysplastic naevi (HDN) with re‐excision vs. observation remains controversial because of lack of evidence about associated melanoma outcomes. Objectives To assess published data on the development of biopsy‐site primary cutaneous melanoma among biopsy‐proven HDN managed with either re‐excision or observation. Methods A systematic review of all published data: a total of 5293 records were screened, 18 articles were assessed in full text and 12 studies met inclusion criteria. No controlled trials were identified. Results Most studies (11 of 12, 92%) were retrospective chart reviews, and one was both a cross‐sectional and cohort study. Many studies (nine of 12, 75%) had no head‐to‐head comparison groups and either only reported HDN that were re‐excised or observed. A total of 2673 (1535 observed vs. 1138 re‐excised) HDN of various grades were included. Follow‐up varied between 2 weeks and 30 years. Nine studies reported that no melanomas developed. Eleven biopsy‐site melanomas developed across three of the studies, six among observed lesions (0·39%) and five among re‐excised lesions (0·44%). Conclusions Based upon the available evidence the rates of biopsy‐site primary melanoma were similarly low among observed lesions and re‐excised lesions. This suggests that HDNs can be observed with minimal adverse melanoma‐associated outcomes. However, all included articles were of low quality and further prospective trials could better guide clinical decision making. What's already known about this topic? Management of histologically dysplastic naevi (HDN) with re‐excision vs. observation remains controversial. A number of studies have suggested that observation may be a reasonable alternative to re‐excision; however, no systematic review summarizing the available data has been conducted. What does this study add? Current evidence suggests that both re‐excised and observed HDN have low rates of melanoma development. Clinical observation of most HDNs is likely a safe practice. However, the evidence is of low quality and is limited by imprecision because of few total observations and events. Linked Comment: Greenwald and Stein. Br J Dermatol 2018; 179:554–555. Plain language summary available online