The utility of ultrasound in patients with melanoma.

The highest quality gray-scale ultrasound images are obtained with high-frequency transducers; however, such high frequencies do not penetrate more than a few centimeters into body tissue. Fortunately, in patients with melanoma, the structures of interest are close to the skin surface, making them ideal targets for examination with high-resolution ultrasound. These include primary cutaneous melanomas, uveal melanomas and the regional lymph nodes draining the skin that lie in the axilla, groin, neck and other locations. Although ultrasound study of primary melanomas arising in the skin and eye has provided some insights, a major role for ultrasound has evolved recently, to provide early detection of metastatic melanoma in regional lymph nodes. Ultrasound is clearly superior to clinical palpation of the nodes during follow-up and, when combined with guided fine-needle biopsy, allows the earliest possible surgical intervention for regional nodal metastases. In the future the use of ultrasound contrast agents may improve the sensitivity of ultrasound in the detection of very small metastatic deposits.