Upfront Definitive Oncoplastic Breast Conservation Surgery in Biopsy Missed Cancers: Our Experience.

False negative rates of image-guided core needle biopsy of breast lesions, range from 0.1 to 2.5%, with most cases coming to light because of radio-pathological discordance. We are forced to consider upfront surgery for such lesions with unknown biology, which precludes us from utilizing preoperative systemic therapies and shared decision-making, to our advantage. We present a series of core biopsy missed breast neoplasms with radio-pathological discordance successfully managed with definitive upfront oncoplastic breast-conserving surgery (OBCS) without diagnostic delay, re-excisions, or compromising on oncological and cosmetic outcomes. This study retrospectively analyzed data from eight female patients assessed for breast-related concerns at our malignant disease treatment center between April 2021 and December 2023. These patients exhibited radio-pathological discordance during the triple assessment of BIRADS-4 breast lesions with two successive image-guided core needle biopsies (CNB) reported negative for DCIS/ invasive cancer. As patients had lump size < 5 cm and clinico-radiologically negative axilla (cN0), the pre-operative systemic staging was not warranted. These cases were discussed in a multi-disciplinary tumor board. Post-MDT consensus, they underwent upfront definitive oncoplastic breast-conserving surgery with intra-operative frozen section analysis (FSA) to confirm the diagnosis and assess margins as well as the need for surgical axillary staging. Subsequent management followed a final histopathological examination, receptor subtype, and guideline-based staging. The mean age of the patients was 54.25 years, all presenting with palpable breast lumps. Primary tumors were mostly located in the upper outer and upper inner quadrants (3 cases each, 37.5%). Intraoperative frozen section analysis revealed invasive breast carcinoma in 5 cases (62.5%), papillary lesions with atypia in 2 (25%), and ductal carcinoma in situ in 1 (12.5%). Subsequent excision showed 4 (50%) invasive ductal carcinomas, 1 (12.5%) invasive lobular carcinoma, and 3 (37.5%) ductal carcinomas in situ. Level I oncoplastic breast-conserving surgery (OBCS) was performed in 5 cases, while level II OBCS was done in 3 cases. Sentinel lymph node biopsy was performed in 5 cases with invasive carcinoma on frozen section. Median follow-up was 10.5 months (range: 3-24 months). Definitive upfront OBCS can be used as a one-stop surgical solution in select patients with missed cancers on biopsy. It can avoid diagnostic delays and reduce re-excision rates without having to compromise on oncological and cosmetic outcomes.