Post-lumpectomy breast calcifications: Can original tumor features assist in determining need for biopsy?

Objective: The objective of our study was to determine whether, in the digital era, imaging features of a primary breast tumor can be used to influence the decision to biopsy ipsilateral breast calcifications that occur following surgery in women treated with breast conservation surgery (BCS). Materials and methods: We retrospectively identified women treated with BCS who subsequently developed suspicious calcifications in the treated breast (BI-RADS 4 or 5) from January 2012-December 2018. Only cases with histopathological diagnosis by stereotactic or surgical biopsy were included. Pathology reports were reviewed, and biopsy results were considered malignant if invasive carcinoma or ductal carcinoma in situ (DCIS) was found. All other results were considered benign. Fisher's exact test was done comparing frequencies of malignancy between those patients whose original tumor had calcifications versus those whose original tumors were not calcified. Results: Of 90 women with suspicious calcifications on a post-BCS mammogram, 65 (72.2%) were biopsy proven benign and 25 (27.8%) were malignant. The original tumor presented without calcifications in 39 patients (43%), and 51 (57%) had calcifications with or without associated mass, focal asymmetry, or architectural distortion. New calcifications were less likely to be malignant if the original tumor presented without calcifications (5/39; 12.8%) as compared to original tumors with calcifications (20/51; 38.5%) [p-value < 0.05]. Conclusion: New calcifications after BCS are significantly less likely to be malignant if the original tumor presented without calcifications. However, with a PPV of 12.8%, even calcifications in a patient with a non-calcified primary tumor require biopsy.