Comparison of rate of development and rate of change for benign and malignant breast calcifications at the lumpectomy bed.

OBJECTIVE: The study purpose was to evaluate the rate of development and the rate of change for benign and malignant breast calcifications at the lumpectomy bed.

MATERIALS AND METHODS: Retrospective review identified 53 new calcifications at the lumpectomy bed in patients with available mammograms and medical records. Breast Imaging Reporting and Data System (BI-RADS) categories were retrospectively assigned on the basis of initial prospective recommendation for yearly follow-up (category 2), 6-month follow-up (category 3), or biopsy (category 4 or 5). Outcomes were defined as benign for no recurrence at the lumpectomy bed on biopsy or follow-up and malignant if biopsy-proven at the lumpectomy bed.

RESULTS: The median rate of development after lumpectomy was 23 months (range, 2-174 months) for benign and 39 months (range, 15-112 months) for malignant calcifications. Fifteen (28%) of 53 calcifications were classified as BI-RADS category 3. Twelve (80%) of 15 were downgraded to BI-RADS category 2 at a median follow-up of 6.5 months (range, 6-16 months); none represented recurrent disease. Three (20%) of 15 were upgraded to BI-RADS category 4 at the 6-month follow-up, one despite stability (benign) and two for increasing pleomorphism (malignant). Nine (17%) of 53 calcifications were classified as BI-RADS category 4 or 5; six (67%) of the nine were malignant and three (33%) were benign at biopsy. Twenty-nine (55%) of 53 calcifications were classified as BI-RADS category 2, none representing recurrent disease.

CONCLUSION: Benign calcifications at the lumpectomy bed usually develop earlier than malignant calcifications, but the rate of development overlaps. Most calcifications initially placed in the probably benign category evolve quickly to more benign or more malignant morphology. Most calcifications heralding recurrence appear suspicious on first presentation.