Stereotactic core breast biopsy of malignant calcifications: diagnostic yield of cores with and cores without calcifications on specimen radiographs

Abstract

Purpose: To retrospectively compare core biopsy diagnosis with final diagnosis at surgical excision in cores with and cores without calcification on specimen radiographs.

Materials and methods: One hundred thirteen consecutive patients underwent vacuum-assisted 11- or 14-gauge needle stereotactic core biopsy for calcifications with malignant histologic results in core samples from 116 lesions. For each lesion, calcification was identified in at least one core at specimen radiography. Cores with and those without calcification seen on magnified specimen radiographs were separately submitted to and reported on by pathologists, who obtained additional levels in cores with calcification. All patients underwent surgical excision of the lesion area within 7 weeks. The pathologic diagnosis in core samples with and those without calcification on specimen radiographs was compared with final diagnosis at surgical excision. Fisher exact test was used for all chi(2) determinations of statistical significance.

Results: Cores with calcification on specimen radiographs were more likely to enable a final diagnosis of malignancy than were cores without calcification (98 [84%] vs 82 [71%] of 116; P =.02). Cores without calcification were significantly more likely to cause a diagnosis of cancer to be missed than were those with calcification on specimen radiographs (13 [11%] vs one [1%] of 116; P <.001). Underestimates of malignancy were more frequent in 14- than in 11-gauge specimens (11 [18%] of 60 vs six [10%] of 56; P =.30). Regardless of needle size, there was no significant difference in underestimation of malignancy between cores with and without radiographically evident calcification (17 [15%] vs 21 [18%] of 116; P =.60).

Conclusion: Specimen radiography is essential to document calcification retrieval. Cores without radiographically demonstrated calcification may fail to show a malignant lesion. Separate identification of calcium-containing cores may assist the pathologist, who can more thoroughly evaluate these cores with additional levels of section.