[The accuracy of frozen sections in the diagnoses of breast lesions].

To evaluate the accuracy in diagnosing breast lesions by frozen sections, 657 consecutive diagnostic biopsies seen during 1982 were reviewed. Of 559 lesions considered benign at frozen sections, 558 were also benign in paraffin sections, the remaining one being a papillary carcinoma (i.e. 1/559 or 0.2% false negative). All 78 cases diagnosed as malignant in frozen sections were also malignant in paraffin sections (i.e. 0% false positive). Of the 20 doubtful cases, in frozen sections, 15 showed a papillary lesions; 7 of them were malignant in paraffin sections and the rest 13 benign. It is concluded that the frozen sections are usefull in the diagnoses of mammary disorders except for those cases with papillary tumors.