[The importance of fine needle biopsy in modern breast diagnosis (author's transl)]

860 mammary tumours were clinically, mammographically and cytologically examined. Only thereafter, the histological diagnosis was established following surgical biopsy. There were found 356 malignant and 504 benign processes. The limited reliability of the individual methods is pointed to. As is proved, the diagnostics can be improved by combining the application of all three methods. On the one hand, a larger number of malignoma or malignoma-suspect processes are discovered, on the other hand, the preoperative diagnostics becomes more reliable. If the 3 methods yield similar findings, the diagnostic probability of error is below 1 per cent. Before, the range of indication was clearly outlined, the technique of punction, obtaining and processing of material was discussed, and the complications and limits of the methods were pointed to.