DIFFERENTIAL-DIAGNOSIS OF MAMMARY-TUMORS WITH VOCAL FREMITUS SONOGRAPHY - PRELIMINARY-REPORT

During sonographic examinations using the new color Doppler technique, maximum-entropy method (MEM), it was discovered, by chance, that arte facts which are produced by vibrations of the thorax can be used to di fferentiate between malignant and benign breast lesions. These artefac ts, in the form of small color pixels, can either be brought about by vocal fremitus known from internal medicine or by humming in a low ton e. In the case of malignant tumors, the color pixels are visible in th e middle of the sonographically portrayed tumor as well as in the surr ounding tissue, whereas in benign tumors the artefacts are only found in the surrounding tissue and are quire clearly not present in the cen ter of the tumor. On the preoperative day, 95 patients with 46 benign and 49 malignant lesions were examined using the method described abov e. In 91% the differential diagnosis was in accordance with the histol ogical results. In seven cases a benign lesion was classified before t he operation as malignant and in two cases malignancy was incorrectly diagnosed as benign. Our explanation of the phenomenon is based on the fact that most benign tumors exhibit a restricted growth and form a c lear-cut boundary with the surrounding tissue, so the vibrations are n ot conducted into the tumor. In contrast, malignant lesions grow by in filtrating the surrounding tissue, allowing the vibrations to be condu cted into the tumor, where they can be demonstrated as small color pix els.