Histological correlation of microcalcifications in breast biopsy specimens.

Hypothesis: Nonpalpable malignant-appearing microcalcifications discovered by mammography geographically target the location of the most important abnormality within the breast. Core needle or open biopsy of these microcalcifications will sample or remove underlying proliferative or invasive disease.

Design: A prospective database of 403 consecutive patients undergoing breast biopsy for nonpalpable abnormalities from July 1, 1994, to December 31, 1996, was reviewed to identify biopsies done for indeterminate microcalcifications. Specimens showing atypical hyperplasia, carcinoma in situ, or invasive carcinoma were identified and reviewed by 1 pathologist. The position of microcalcifications larger than 100 microm were recorded in reference to the histological findings.

Setting: A 450-bed referral community teaching hospital in rural Wisconsin.

Patients: Indeterminant microcalcifications were identified on mammograms in 167 (41.4%) of 403 patients. Sixty-one (36.5%) of 167 biopsy specimens contained atypical hyperplasia, carcinoma in situ, or invasive carcinoma, and the slides of these 61 initial breast biopsy specimens were reviewed.

Main Outcome Measures: Relationship of breast histopathological findings to microcalcifications.

Results: In these 61 specimens, 82 areas of atypical hyperplasia, carcinoma in situ, or invasive carcinoma were noted. The microcalcifications correlated with these areas in 43 (52%) of 82 areas on slide review and were present in the most important abnormality in 33 (54%) of 61 biopsy specimens.

Conclusions: Indeterminant microcalcifications identified by mammography may not target the exact location of underlying breast disease. Careful evaluation of the entire biopsy specimen and close follow-up of patients with benign pathologic findings are recommended.