Dermoscopy aids biopsy decisions

New York - Using dermoscopy to differentiate suspicious lesions from benign ones is helping dermatologists make better, more selective decisions about biopsy excisions.

According to Giuseppe Argenziano, M.D., Ph.D, the diagnostic tool can also serve to double- check a clinician's naked-eye examination and diagnosis.

Presenting at the American Academy of Dermatology's Academy '04 here, Dr. Argenziano explained how dermoscopy helps a dermatologist classify lesions and identify melanocytic and non-melanocytic ones. He has used dermoscopy for more than 10 years and is an assistant professor in the department of dermatology at Second University of Naples, Italy.

"The most common mistake is to judge a lesion as a possible melanoma when it is, indeed, a benign nevus," he says.

Although other devices to help discriminate pigmented skin lesions are under investigation, Dr. Argenziano says, "none of them, at the moment, (have been) demonstrated to perform better than an experienced clinician using dermoscopy." He acknowledges that currently no available diagnostic method, including dermoscopy, achieves 100 percent diagnostic accuracy for melanoma.

Prior to using dermoscopy to examine a lesion, he says, the lesion should be evaluated clinically using visual information. The ABCDE criteria (asymmetry, border irregularity, color variegation, diameter more than 5 mm and enlargement of the lesion in recent months) are well-accepted tools for melanoma screening that Dr. Argenziano suggests using first. As part of the clinical exam preceding dermoscopy, he also recommends considering the patient's age, gender and lesion location, noting that melanoma is quite rare in children and is more frequently found on men's backs and women's legs.

Double-check lesions Whether or not such a clinical examination raises the suspicion of melanoma, Dr. Argenziano says he checks nearly all lesions again using dermoscopy.

"Most often dermoscopy just confirms the diagnosis I already did by the naked eye," Dr. Argenziano says. "However, sometimes it is opening my mind to new possibilities."

He says today's hand-held dermoscopes with polarized light no longer require the application of oil to the patient's skin, so this feature can make the recheck process with a dermoscope "very fast and simple."He notes that dermoscopy does not always confirm a clinical examination but can sometimes reverse a diagnostic decision, such as in a patient with dysplastic moles. It could be that a visual examination of the moles raises the clinician's suspicion of melanoma, but dermoscopy shows the lesions to be clinically benign. The opposite can also be true; a lesion that appears benign to the naked eye can prove to have some atypical, melanocytic features when examined with dermoscopy.

Helps visualize criteria Dermoscopy enables a dermatologist to better visualize the basic criteria for a melanocytic lesion: asymmetry of color and structure, atypical pigment network and blue-white structures. Dermoscopy can help a clinician distinguish those features from the comedo-like openings and milia-like cysts found in seborrheic keratosis.