[Ultrasound microscopy of skin sections]

In vivo ultrasound examination has been introduced into dermatology as a non-invasive diagnostic technique. The resolution capacity, however, has been limited so far, and the in vivo ultrasonic features have not been fully understood. Using high frequencies (GHz range) in acoustic microscopy, we have been able to achieve a resolution comparable to that in light microscopy. In a first step, we examined normal human skin sections and compared them to histological specimens. The following study on melanocytic nevi, malignant melanoma, and metastases of melanoma showed that their acoustic images were more pronounced than those of the surrounding tissue. The echo intensity of solid basal cell carcinoma and squamous cell carcinoma resembled that of the epithelium. The structures found in acoustic microscopy can be correlated to those seen in light microscopy.