In last years the incidence of skin tumors is increasing. Skin tumor diagnostics is based mainly on clinical exa- mination and its accuracy depends on an experience of dermatologist. Patient’s history, macroscopic findings, sometimes with use of magnifying glass, are considered and thus two - dimensional picture of lesion is obtained. However, the information about tumour thickness, which is a basic clue to optimal therapy planning, especially considering laser or cryosurgery treatment, is missing. Ultrasound devices have been used for several decades in clinical medicine. Their utilization in dermatology is rather recent. Except for tumour diagnostics, they are used for a therapeutical effect monitoring of inflammato- ry diseases localized in dermis or to diagnose changes in the subcutaneous tissue. The method is widely used in experimental medicine. The mostly used probes working with the frequency of 20 MHz enable to imagine struc- tures 7 mm deep. The main echogenous structure of the dermis is a network of collagen fibres – its alteration cau- ses a change in the ultrasound image. In particular cases the method could contribute to the differential diagnos- tics but the main scope is still in the detection of structural changes. This article aims to introduce the possibilities and limitations of this new non-invasive examination method to our dermatologists. By virtue of decreasing acquisition costs it might become readily available.

        Key words: ultrasound – A-mode – B-mode