| Abstract: | The diagnostic accuracy of frozen section (FS) examination and intraoperative cytology (IOC) has been compared in two different series of breast biopsies in which only one of the two methods has been used. The intraoperative results have been compared with the final histological diagnoses. Five-hundred-ten cases have been investigated by using FS only, and 407 by means of IOC. The two series were comparable because they included the same pathologies; moreover we have subdivided each series into four groups of pathologies to better evaluate the diagnostic accuracy of two methods. The total diagnostic accuracy of FS has been 93.13% vs. 95.-33% of IOC The value of diagnostic accuracy of FS and IOC in the four sub-groups substantially overlapped; there was only a little difference in the group of “various lesions” in which the diagnostic accuracy of IOC was higher. No false positive has been observed in IOC. FS have produced one false positive (0.19%), whereas false negatives have amounted to 1.77% for IOC and to 1.72% for FS. Deferred diagnoses have been 2.95% in IOC and 4.90% in FS examination. For both methods according to Galen and Gambino the following values have been calculated: sensitivity, specificity, efficiency, and predictive value. By comparing the data, the value of the cytological examination in the intraoperative diagnoses results is evident mainly when the latter is coupled with the gross observation. Causes of diagnostic errors clearly overlap both in IOC and in FS: (1) lesions with a fibroadenomatous appearance can involve an overdiagnosis or an underdiagnosis; (2) low-grade lesions like tubular carcinomas or in situ lobular carcinomas can be interpreted as benign; (3) the differential diagnosis of intraductal lesions may be very difficult, and a conservative approach is the best choice; and (4) infiltrating lobular carcinoma may be neglected both in FS and IOC. The few disadvantages of the cytologic method are offset by its low cost, the wider sampling, the possibility of sparing tissue for further investigations (such as steroid receptors, cellular kinetic, electron microscopy, and other biological studies) proved more useful in prognostic evaluation of breast cancer. |
