Clinical Decision Making Based on Histopathologic Grading and Margin Status of Dysplastic Nevi FREE

The purpose of the present study was to determine how clinicians elect to treat a histologic dysplastic nevus (DN) given a reported grade of the dysplasia and margin involvement on a biopsy report.

An anonymous survey was distributed to the members of the Chicago Dermatologic Society during the annual meeting in March of 2009. Respondents were asked what clinical decisions they would make based on hypothetical pathology reports of varying histopathologic grades of DN with and without margin involvement. For survey purposes, we characterized DN as histopathologically displaying mild, moderate, or severe atypia. We did not specify if the nevi were primarily graded on the architectural or cytologic features. A total of 6 case scenarios were presented to the respondents. The survey questions were presented as follows:

Biopsy report states the patient has a mildly (or moderately/severely) dysplastic nevus with positive (or clear) margins. Elect to: Observe, Re-excise or Other.

A freehand response was allowed for the “Other ” option. Institutional review board approval was waived for this anonymous survey.

Of the 158 surveys distributed, 101 were returned for a 58% response rate. There was no significant difference in the probability of electing to reexcise nevi with mild vs moderate dysplasia in patients with clear margins reported on pathologic evaluation (Figure, A). If the margins were positive, there was a significantly greater probability of electing to reexcise the DN for all grades of dysplasia (Figure, B). The greatest quantitative shift in decision making (from observe to reexcise) as a function of involved margins was seen for DN with moderate dysplasia. Specifically, the decision to reexcise DN with moderate dysplasia inverted from 9% to 81% of respondents.

This study finds that both grade and margin status are important variables in determining surgical decisions; margin status is most influential when applied to DN of moderate grade. Margin status does not appear to be as critical for clinical decision making of DN with mild or severe dysplasia.

Previous studies,^1- 2 also using surveys, have attempted to elicit the reexcision rate of DN histologically confirmed, but those studies did not directly address the histologic grade of the lesion or the margin status of the biopsy specimen. The responses from both of those studies indicated that both the margin status and the degree of dysplasia had some role in the decision to reexcise. The present study addresses the effect of both degree of atypia and margin status reported on the clinician's decision to observe or reexcise a DN.

The DN is a controversial subject in dermatology, and although there are no universally accepted criteria for grading DN (or the biologic consequence of these lesions), it remains common clinical practice. In our small sample, 83% of respondents indicated that the dermatopathology reports they receive comment on the grade of a dysplastic nevus.

Our findings are relevant because there is mounting evidence that reexcision of lesions with low-grade atypia (mild and moderate DN) may not be necessary, even when positive margins are found^3- 4; the recurrence rates of these nevi are low, and there are no reports of subsequent development of melanoma in these lesions. Larger prospective trials are still needed to help define a standard of care with respect to histopathologically proven DN.

Our survey demonstrates the likely clinical decisions given a pathology report defining the degree of histopathologic atypia and margin involvement. It is helpful for dermatopathologists to know the clinical consequences of their pathology report and for other clinicians to see how their colleagues approach these controversial lesions.