Re-excision May Not Be Necessary for Dysplastic Nevi With Severe Atypia

By David L. Levine

November 29, 2016

NEW YORK (Reuters Health) - Dysplastic nevi with severe atypia (severely dysplastic nevi, or SDN) are frequently re-excised for fear they may represent early melanoma, but a new study suggests routine re-excision may not be necessary.

At the University of Pittsburgh Medical Center in Pennsylvania, researchers reviewed data on 451 patients with 499 SDN whose first lesion was biopsied between 1994 and 2004.

The mean age at diagnosis was 41. The median follow-up was 11.9 years.

Prior to being diagnosed with SDN, 61 patients (13.5%) had been diagnosed with melanoma.

Only first biopsied SDNs were included in the study. Dermatologists performed 29.7% of biopsies, and dermatopathologists reported the pathology in 67.4% of cases.

Re-excision of the dysplastic nevus was performed in 36.6%. "Two melanomas were diagnosed in the re-excision specimens," the authors reported online November 9th in the Journal of the American Academy of Dermatology. "Subsequent metastatic melanoma developed in seven patients, all of whom had a history of melanoma."

They note that margin comments influenced the decision to re-excise.

Coauthor Dr. Timothy Patton said his team was surprised at how few SDNs were re-excised. But "when you look at the fact that most of the lesions biopsied had clear margins, this number makes a little more sense," he told Reuters Health by email. "When we looked just at the lesions that had a positive margin, the percentage of cases that underwent re-excision was higher - almost 60%, but this number is still low given the fact that almost all dermatologists will probably perform re-excision in this instance."

Dr. Patton continued, "If there was no prior history of melanoma and patients were diagnosed with a dysplastic nevus with severe atypia, no subsequent cases of metastatic melanoma occurred, even if the original biopsy site did not undergo re-excision."

"We wouldn't necessarily say that we were surprised by this finding, but it was one of the questions which we sought to answer when we were designing the study," Dr. Patton said. "For physicians who treat patients diagnosed with a dysplastic nevus with severe atypia and the margins are free, and there are no additional clinical or histologic concerns, re-excision may not be necessary."

Dr. Ali Hendi, a clinical assistant professor of dermatology at the Georgetown University Medical Center in Washington, DC, told Reuters Health by phone that while the study "sheds some light on the difficulties of treating patients with severely dysplastic nevi," discordance among pathologists remains a problem.

"For example," said Dr. Hendi, "in the study there were three cases that were first classified as dysplastic nevi but on subsequent review the pathologists involved with the study changed the diagnosis to melanoma. This study is useful because it adds to the knowledge base we rely on managing patients with SDN but also shows that better diagnostic tools are needed, which the authors allude to in the study.

SOURCE: http://bit.ly/2fYG9hk

J Am Acad Derm 2016.

Benjamin Hidalgo-Matlock

Skin Care Physicians of Costa Rica

4000-1054

2208-8206

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