Although shave biopsies have the potential to hamper accurate diagnosis and staging of melanoma, a recent study indicates that such procedures are a reasonably safe and accurate method for the initial evaluation of malignant melanoma.
In their report for the Journal of the American College of Surgeons (2011;212:454-462, http://download.journals.elsevierhealth.com/pdfs/journals/1072-7515/PIIS1072751510012846.pdf), lead study author Jonathan S. Zager, MD, of the Moffitt Cancer Center in Tampa, Florida, and colleagues described shave biopsy of cutaneous lesions as simple, efficient, and commonly used clinically. However, they acknowledged that shave biopsies can lead to misdiagnosis and inaccurate staging due to partial sampling and under-representation of the lesion for a variety of reasons. (Although the American Academy of Dermatology currently recommends excisional biopsy for diagnosing skin lesions suspected of being melanoma, it is infrequently performed. “This may be due in part to the low accuracy of clinical diagnosis of melanoma, with reported rates as low as 42%,” noted the investigators.)
Zager and associates retrospectively analyzed the shave biopsies of 600 patients aged 17 to 91 years (median age 62 years) with suspicious skin lesions over a 3-year period. On shave biopsy, 531 (88.5%) of the lesions were diagnosed as invasive melanoma. Definitive surgical wide excision revealed residual melanoma in 22% (133 patients). However, the detection of residual melanoma in these patients only led to upstaging of the tumor in 3% (18) of patients, indicating that shave biopsy yielded tumor stage and depth data that were accurate in 97% of all patients.
“These data challenge the surgical dogma that full-thickness excisional biopsy of suspicious cutaneous lesions is the only method that can lead to accurate diagnosis,” concluded the investigators. “Data obtained on shave biopsy of melanoma are reliable and accurate in the overwhelming majority of cases (97%). The use of shave biopsy does not complicate or compromise management of the overwhelming majority of patients with malignant melanoma.”