Shave better than punch biopsy

Sydney, Australia - The shave biopsy may be a more accurate way to diagnose dysplastic nevi than the punch biopsy technique, according to a new study.

Stephen Lee, M.D., head of the department of dermatology, Concord Repatriation General Hospital, Sydney, Australia, and colleagues set out to address the controversial subject of how best to manage dysplastic nevi by conducting a pilot study of more than 100 specimens of pigmented skin lesions clinically diagnosed as dysplastic nevi.

"The specimens were obtained by either punch or shave biopsy for histological examination and, subsequently, all lesions were excised for further histological examination," Dr. Lee says. "The lesions included in this study were not considered malignant prior to biopsy."

Specifically, 21 of 22 shave biopsies were concordant with their respective excision specimens, and 29 of 41 punch biopsies were concordant with their respective elliptical excision specimens. Sixty-six percent of the shave biopsy specimens had been completely excised, compared to 21.2 percent of the punch biopsy specimens, according to the study.

Although punch and shave biopsies are not recommended as first-line management when dermatologists are faced with a clinically obvious malignant melanoma,such biopsies of a clinically unsuspected melanoma can provide histologic information that is useful in planning definitive surgical treatment of the melanoma, Dr. Lee says.

"There is no proof that the prognosis of malignant tumors of various organs, including melanomas, is less favorable if a biopsy is performed prior to definitive treatment, provided, of course, that definitive treatment is initiated as soon as the histologic diagnosis has been made," he says.

According to Dr. Lee, there are at least two other ways in which shave biopsies can impact on current dermatological practice - particularly medico-legally:

"I emphasize that the study is a small retrospective pilot study, from which categoric and dogmatic conclusions are not intended to be drawn. In reality, one cut may not suit all," Dr. Lee says. "Rather, this study is intended to invite clinicians to consider various biopsy options before choosing the most appropriate method on a case-by-case basis. Further investigations are necessary for more light to be shed on this subject."