Molecular Subtype Discordance in a Young Woman with Synchronous Bilateral Breast Cancer: A Case Report

Molecular subtype discordance in bilateral synchronous breast cancer is a relatively uncommon entity that poses unique therapeutic challenges. Here we report the case of a 35-year-old woman who presented to our clinic with synchronous bilateral breast cancer (SBBC), with stage IIA triple-negative disease in the right breast and a stage IIB hormone-sensitive tumor in the left breast. She was treated with bilateral modified radical mastectomy and axillary node dissection followed by adjuvant chemotherapy, radiotherapy, and a five-year regimen with daily tamoxifen. To date, the patient remains asymptomatic and free of disease recurrence 78 months after initiating treatment. Little is known about SBBC with a discordant molecular subtype and reports about this entity are scarce. Future studies aimed at identifying the optimal management strategy for this disease are needed.