The value of intraoperative diagnosis in breast lesions.

UNLABELLED Frozen section examination is aimed at making a preoperative diagnosis, determining the benign or malignant nature of a breast lesion, but also the most suitable surgical procedure. The sensitivity and specificity of this method and the causes of discrepancies were analyzed in a retrospective study of 2 177 breast lesions. METHOD 1,150 frozen sections from 2,177 breast lesions were performed in the interval 1999-2005. The sections made at the open door cryostat and measuring 5 microm were stained with rapid Hematoxylin-Eosin. The following terms were used for describing the intraoperative diagnosis: negative, positive, and await paraffin section. After the frozen section diagnosis was made, the frozen tissue was thawed to room temperature and fixed in formalin overnight for further paraffin processing. The remaining unfrozen tissue was processed into a paraffin section. RESULTS The number of cases and the number of frozen sections increased from 1999 (341 cases, 87 frozen sections) to 2005 (441 cases, 220 frozen sections). Mean sensitivity (a/a+c) was 94%, and mean specificity (d/b+d) was 99%. The false positive cases accounted for 0.08%, while the false negative ones for 2.26%. In 7% of the cases the diagnosis could not be made on frozen section. CONCLUSIONS Despite the raging popularity of aspiration cytology, frozen section still stands out as the method of choice for rapid diagnosis. Frozen section is not indicated to be performed on mammographically detected lesions, small lesions, papillary lesions, proliferating fibrocystic disease, or tubular carcinoma.