Abstract
Background: Oncoplastic breast surgery allows high-volume excision without compromising aesthetics. We aimed to analyze the probability of identifying high-risk malignant lesions in the contralateral breast.
Materials and Methods: The study analyzed patients who underwent oncoplastic surgery between January 2000 and December 2023. All the patients underwent a preoperative assessment of the contralateral breast using mammography, ultrasonography, and breast MRI. Pathology reports were reviewed to identify malignant and high-risk lesions.
Results: 38 patients had left-sided breast cancer, and 44 had right-sided breast cancer. The distribution of the pathology results was invasive ductal carcinoma in 68 patients, invasive lobular carcinoma in 11 patients, malignant phylloid tumor in one patient, borderline phylloid tumor, and metaplastic carcinoma in one patient. In contralateral breast pathology, 12 patients had low-risk lesions and 12 patients had high-risk lesions. Two patients had invasive tumors in the contralateral breast.
Conclusion: Although detailed preoperative imaging is performed in patients undergoing oncoplastic breast surgery, a significant number of high-risk or malignant lesions may be present in the contralateral breast.

Key words: Oncoplastic breast surgery, breast cancer, accidental premalignant, breast-conserving surgery