Calcifications in breast biopsy specimens: discrepancies in radiologic-pathologic identification. To analyze the effectiveness and accuracy of the diagnostic process from screening mammography to final diagnosis at pathologic examination, the authors conducted a prospective study of 277 consecutive patients who underwent 291 mammographically directed biopsies of nonpalpable lesions. Of the 170 lesions that demonstrated findings consistent with calcification on preoperative mammograms and radiographs of specimens, 12 (7.1%) were not described by the pathologist as being calcified. These discrepancies were due to inadequate sampling in three cases (25%), lack of explicit description by the pathologist in four (33%), presence of oxalate crystals that required examination with polarizing lenses in two (17%), and unexplained loss of tissue probably related to processing in three (25%). Of the 121 lesions that did not demonstrate findings consistent with calcification at radiography, eight (6.6%) were described as calcified by the pathologist. The authors recommend a protocol for avoiding these discrepancies that involves performance of a more comprehensive examination of histologic sections by the pathologist, including the use of polarizing lenses, if necessary, and radiographic reexamination of paraffin-embedded tissue blocks with subsequent step sectioning by the pathologist when results are positive. 