Superparamagnetic iron oxide (SPIO) for axillary mapping in patients with ductal carcinoma in situ undergoing mastectomy: single-institution experience.

PURPOSE: Unnecessary axillary surgery can potentially be avoided in patients with DCIS undergoing mastectomy. Current guidelines recommend upfront sentinel lymph node biopsy during the index operation due to the potential of upstaging to invasive cancer. This study reviews a single institution's experience with de-escalating axillary surgery using superparamagnetic iron oxide dye for axillary mapping in patients undergoing mastectomy for DCIS. METHODS: This is a retrospective single-institution cross-sectional study. All medical records of patients who underwent mastectomy for a diagnosis of DCIS from August 2021 to January 2023 were reviewed and patients who had SPIO injected at the time of the index mastectomy were included in the study. Descriptive statistics of demographics, clinical information, pathology results, and interval sentinel lymph node biopsy were performed. RESULTS: A total of 41 participants underwent 45 mastectomies for DCIS. The median age of the participants was 58 years (IQR = 17; range 25 to 76 years), and the majority of participants were female (97.8%). The most common indication for mastectomy was diffuse extent of disease (31.7%). On final pathology, 75.6% (34/45) of mastectomy specimens had DCIS without any type of invasion and 15.6% (7/45) had invasive cancer. Of the 7 cases with upgrade to invasive disease, 2 (28.6%) of them underwent interval sentinel lymph node biopsy. All sentinel lymph nodes biopsied were negative for cancer. CONCLUSION: The use of superparamagnetic iron oxide dye can prevent unnecessary axillary surgery in patients with DCIS undergoing mastectomy.

Case of second primary breast cancer in ectopic breast tissue and review of the literature.

Accessory breast tissue (ABT) is found in approximately 2%-6% of the female population and are subject to most of the physiological and pathological changes that occur in pectoral breast. Primary breast cancer occurring in ABT is a rare occurrence and a second primary breast cancer occurring in an accessory breast has never been reported. We report the case of a 60-year-old woman with a history of mastectomy for left breast cancer 5 years prior to presentation, who presented with an enlarging right axilla mass found to be a second primary breast cancer in an accessory tissue on biopsy. Many physicians are unfamiliar with the clinical presentation of accessory breast cancer due to the rarity of the condition and this ultimately results in delayed diagnosis and advanced disease at presentation. It is therefore prudent that physicians have a high index of suspicion when patients present with axillary masses.