Research Original Investigation Atypical (Dysplastic) Nevi Outcomes of Surgical Excision and Association With Melanoma Kavitha K. Reddy, MD; Michele J. Farber, MD; Jag Bhawan, MD; Roy G. Geronemus, MD; Gary S. Rogers, MD CME Quiz at OBJECTIVE To evaluate the effect of surgical excision, performed after biopsy diagnosis of jamanetworkcme.com and dysplastic nevus, on final diagnosis, melanoma prevention, and melanoma detection. CME Questions page 1004 DESIGN, SETTING, AND PARTICIPANTS Outcome study using retrospective review conducted in an academic dermatopathology practice (Boston Medical Center Skin Pathology Laboratory) that receives specimens from community and academic practices across the United States. Consecutive patient pathology samples of dysplastic nevi and cutaneous melanomas evaluated between September 1, 1999 and March 1, 2011, and identified using systematized nomenclature of medicine codes were included. MAIN OUTCOMES AND MEASURES In dysplastic nevi cases, the rate of clinically significant change in diagnosis and the rate of melanoma detection as a result of excision. In melanoma cases, the rate and characteristics of association with dysplastic nevus. RESULTS Of dysplastic nevi, 196 of 580 (34%) showed a positive biopsy margin, increasing with grade of atypia (P < .001); 127 of 196 with positive biopsy margin received excision (65%), performed more often as grade of atypia increased (P < .001). Two excisions (2 of 127, 1.6%) resulted in a clinically significant change in diagnosis, from biopsy-diagnosed moderately-to-severely dysplastic nevi before excision to melanoma in situ after excision. In melanomas (n = 216), in situ and superficial spreading subtypes were more often associated Author Affiliations: Laser & Skin Surgery Center of New York, New with dysplastic nevi (20% and 18%, respectively) (P = .002), most often of York, New York (Reddy, Geronemus); moderate-to-severe or severe grade. Departments of Dermatology, Jefferson Medical College, CONCLUSIONS AND RELEVANCE Excision of biopsy-diagnosed mildly or moderately dysplastic Philadelphia, Pennsylvania (Farber); Boston University School of nevi is unlikely to result in a clinically significant change in diagnosis, and risk of Medicine, Boston, Massachusetts transformation to melanoma appears very low. Moderately-to-severely and severely (Bhawan); Tufts University School of dysplastic nevi are more often associated with melanoma, and excision may be beneficial for Medicine, Boston, Massachusetts melanoma detection or prevention. (Rogers). Corresponding Author: Kavitha K. Reddy, MD, Laser & Skin Surgery JAMA Dermatol. 2013;149(8):928-934. doi:10.1001/jamadermatol.2013.4440 Center of New York, 317 E 34th St, Published online June 12, 2013. 11th Floor, New York, NY 10016 ([email protected]). lark et al1 described the atypical, or dysplastic, nevus plastic nevus with positive histologic margin, there is signifi- as having unusual clinical and pathologic features cant variation and lack of consensus in subsequent C found in individuals or families predisposed to management.6 melanoma. A National Institutes of Health Consensus Surgical excision of the dysplastic nevus biopsy site with Conference2 further defined atypical nevi as having diam- a 2- to 3-mm margin of normal skin is frequently performed. eter greater than 5 mm, color or border irregularity, and cer- The goal of excision is to confirm the biopsy diagnosis, to en- tain histologic features. Evidence supports observations sure complete removal due to concerns of future malignant that the presence of atypical nevi is associated with transformation, or both. These goals include melanoma de- increased overall melanoma risk.3 tection and prevention. The lifetime transformation risk of an Atypical nevi are common, with an incidence of 2% to 8% “average” dysplastic nevus into melanoma is estimated at 1 in in white patients.4,5 Many are biopsied to evaluate for 10 000, though risk likely varies with grade of atypia.7 In ad- melanoma.4 Management of a biopsy-proven dysplastic (atypi- dition, excision is sometimes performed to eliminate risk of a cal) nevus with a positive histologic margin remains ill defined.6 recurrent nevus, a benign lesion that rarely may be difficult Particularly after a biopsy finding of mildly or moderately dys- to distinguish from melanoma.8 Disadvantages of excision in- 928 JAMA Dermatology August 2013 Volume 149, Number 8 jamadermatology.com Downloaded From: https://jamanetwork.com/ on 09/24/2021 Atypical (Dysplastic) Nevi Original Investigation Research Table 1. Characteristics of Dysplastic Nevi on Biopsy and Excision Dysplastic Nevi, No. (%) Dysplastic Nevus Cases, Positive Biopsy Surgical Residual Clinically Significant Grade No. Margina Excisiona Lesion Change in Diagnosis Mild 155 17 (11) 2 (12) 1 (50) 0 Mild to moderate 90 17 (19) 9 (53) 2 (22) 0 Moderate 207 83 (40) 52 (63) 20 (38) 0 Moderate to severe 109 68 (62) 55 (81) 17 (31) 2 (3.6)b Severe 13 11 (85) 9 (82) 2 (22) 0 Abbreviation: NA, not applicable. Unspecified 6 0 NA NA NA a P < .001. Total 580 196 (34) 127 (65) 42 (33) 2 (1.6) b Melanoma in situ. were diagnosed by a board-certified dermatopathologist. Dys- Figure 1. Grades and Characteristics of Dysplastic Nevi plastic nevus grade of atypia was diagnosed using criteria sum- marized by Arumi-Uria et al.9 Biopsy reports dated between Excision performed after positive biopsy margin September 1, 1999, and March 1, 2011, reporting a pathologic Excision shows residual lesion diagnosis of dysplastic nevus were reviewed retrospectively Excision results in significant 90 change in diagnosis in reverse chronologic order until 580 cases were reviewed. 80 Positive biopsy margin Dysplastic nevi characteristics of gross pathologic size, grade 70 of atypia, anatomic location, and biopsy margin positivity were 60 recorded. In cases reporting a dysplastic nevus with a posi- tive biopsy margin, records were reviewed for surgical exci- 50 sion. Surgical excision of the lesion with a 2- to 3-mm margin 40 of normal skin followed by closure of the skin is the standard 30 Dysplastic Nevi, % Dysplastic Nevi, method for removal of a biopsy-diagnosed dysplastic nevus. 20 If an excision was performed, date of excision, presence of re- 10 sidual lesion on pathologic examination, and final pathologic diagnosis were recorded. Concordance of biopsy diagnoses 0 with excision diagnoses was recorded. Clinically significant Mild Mild to Moderate Moderate to Severe Moderate Severe changes in diagnosis upon excision were recorded, defined as Degree of Dysplasia severe atypia or melanoma upon excision of biopsy- diagnosed mildly-to-moderately or moderately dysplastic nevi, Grade of dysplastic nevus and association with biopsy margin positivity, and defined as melanoma upon excision of biopsy-diagnosed frequency of excision after positive biopsy margin, frequency of residual nevus in excision specimen, and clinically significant change in diagnosis upon moderately-to-severely or severely dysplastic nevi. excision. Pathology reports dated between September 1, 1999, and March 1, 2011, reporting a diagnosis of primary cutaneous mela- noma were also reviewed, until a limit of 216 cases. Mela- clude risks of scarring and surgical complications and utiliza- noma type, depth, presence of associated scar, and presence tion of health resources. of associated dysplastic nevus were recorded. If an associ- The management of dysplastic nevi significantly impacts ated dysplastic nevus was present, grade of atypia was re- individual and public health. The impact of surgical excision corded. In cases of melanoma with associated scar, records of dysplastic nevi on goals of melanoma detection and pre- were reviewed, and any history of biopsy-diagnosed dysplas- vention has not been well-studied. Our objectives were to tic nevus at the melanoma site was recorded. evaluate the impact of surgical excision of biopsy-diagnosed dysplastic nevi on final diagnosis, on melanoma detection, and Statistical Analysis on melanoma prevention through analysis of concordance of Observed characteristics of dysplastic nevi and primary cuta- biopsy and excision diagnoses and examination of the risk of neous melanomas were summarized using counts and pro- dysplastic nevus transformation to melanoma. portions. For dysplastic nevi, biopsy margin positivity, fre- quency of excision after positive biopsy margin, frequency of residual nevus upon excision, and clinically significant change Methods in diagnosis upon excision were summarized within catego- ries of dysplastic nevus grade. For cases of dysplastic nevus Study Design with positive biopsy margin, anatomic location and size were Study approval was granted by the Boston Medical Center in- also summarized within categories of dysplastic nevus grade. stitutional review board. The Boston Medical Center Skin Pa- In primary cutaneous melanoma cases, presence and grade of thology Laboratory database was searched using system- associated dysplastic nevus, presence of associated scar, and atized nomenclature of medicine (SNOMED) codes for history of biopsy-proven dysplastic nevus at the melanoma site dysplastic nevi and for primary cutaneous melanoma. All cases were summarized within categories of melanoma type and jamadermatology.com JAMA Dermatology August 2013 Volume 149, Number 8 929 Downloaded From: https://jamanetwork.com/ on 09/24/2021 Research Original Investigation Atypical (Dysplastic) Nevi Table 2. Association of Dysplastic Nevus Grade With Biopsy Margin Positivity, Anatomic