Unforeseen complications of pembrolizumab in breast reconstruction post-mastectomy

A 53-year-old post-menopausal Indian female presented with invasive ductal carcinoma, treated with neoadjuvant chemotherapy and pembrolizumab due to a PD-L1 combined positive score of 5. Following a right mastectomy and axillary dissection, she received a breast expander and AlloDerm™ graft. After resuming pembrolizumab and paclitaxel postoperatively, she developed severe breast redness and high-grade fever, necessitating expander removal due to suspected pembrolizumab-induced complications. This case underscores the unique and severe adverse effects of pembrolizumab on breast reconstruction, highlighting the need for careful monitoring and management in patients undergoing similar treatments.