Dermoscopy useful in melanoma screening

The examination of equivocal skin lesions by dermoscopy enhances diagnostic discrimination of melanomas from benign lesions and reduces the number of equivocal lesions excised for diagnostic verification, according to a report in the May Journal of the American Academy of Dermatology.

In dermascopic evaluations, oil is used to increase the transparency of the stratum corneum of pigmented skin lesions. A specialized optical system is then employed.”Up to now, studies were performed on series of cases already excised or planned for excision,” Dr. Paolo Carli from University of Florence, Italy told Reuters Health. “Therefore, they dealt with diagnostic simulation instead of with in vivo diagnosis. [Our study] is particularly relevant regarding decisions about lesion management.”Dr. Carli and colleagues investigated the impact of dermoscopy on lesion management during routine evaluation of 913 subjects referred to a pigmented lesion clinic.Dermoscopy was used to examine about half the pigmented skin lesions after they were classified as suggestive or equivocal by naked-eye examination. After dermoscopy, only 17.8% of lesions were deemed suggestive or equivocal and referred to operation, the authors report.Among the patients for whom digital dermoscopy was available for follow-up, a higher percentage of patients (35.8%) were classified as having a suggestive or equivocal lesion. “The possibility of submitting every lesion defined equivocal by dermoscopy to digital follow-up probably induced clinicians to increase the number of these lesions by lowering their threshold of suspicion,” the investigators write.Nevertheless, the rate of surgical excision was significantly reduced in patients randomized to dermoscopy (46% reduction) and in patients randomized to dermoscopy with digital dermoscopy follow-up (57% reduction), the results indicate.Apart from dermoscopy, factors associated with a lower likelihood of surgical excision were younger age and the absence of atypical nevi, the researchers note.Only 2 patients, both in the dermoscopy with digital dermoscopy follow-up group, were later diagnosed with superficial spreading malignant melanomas, the report indicates.”The use of dermoscopy is associated with clinically relevant changes in lesion management, with a significant reduction of the frequency of excisional biopsy of equivocal lesions made for diagnostic verification,” Dr. Carli said.”The possibility of follow-up of the lesion, by means of digital dermoscope (instead of clear-cut decision of ‘yes’ or ‘no’ on an excision), is followed by the risk – not negligible – of leaving a melanoma unexcised,” Dr. Carli cautioned. “The message is that follow-up of equivocal lesions may not be an advisable procedure.”(Source: J Am Acad Dermatol 2004;50:683-689: Reuters Health News: Will Boggs, MD: June 2004)