24 Estimated Rate of Malignancy in Breast Lesions After Discordant Pathology and Imaging

Background

Abnormalities on screening mammograms are often biopsied using minimally invasive techniques to have a pathologic diagnosis, including core needle biopsies or vacuum-assisted core needle biopsies. In cases with discordance between imaging and pathology, patients often undergo an excisional biopsy for conclusive diagnosis.

Materials and Methods

We performed an institutional retrospective chart review for all adult patients who underwent excisional biopsy for discordant imaging and pathology from 2010 to 2020. We evaluated rate of final benign, borderline, or malignant pathology and assessed associated mammography findings, biopsy pathology findings, and patient history. We performed a logistic regression model for factors associated with risk of upstaging to borderline or malignant pathology.

Results

Fifty-eight patients met inclusion criteria. On excisional biopsy pathology, 36 (62%) had benign pathology, 13 (22%) had borderline pathology, and 9 (16%) had malignant pathology. Mammography findings differed between benign, borderline, and malignant pathology groups (P = .0304). The malignant group had a higher rate of mass (67%) or calcifications (33%) findings on mammography. On multivariable analysis, only palpable lesions had a higher risk of upstage to malignancy (adjusted OR 7.50, 95% CI 1.26-44.70) (Table).

Conclusion

This study is a small, retrospective study that shows an overall low rate of upstage to malignancy based on imaging and biopsy pathology discordance. It is important for patients and providers to understand the likelihood of the lesion being malignant when discussing a more invasive procedure, such as excisional biopsy. Further studies with larger sample size are important to further illuminate differences in risk of malignancy.