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.

Learning points: Among patients with early triple-negative breast cancer, the combination of pembrolizumab with neoadjuvant chemotherapy enhances outcomes compared to chemotherapy alone.Early recognition is essential for managing pembrolizumab-induced complications, as demonstrated by the need for expander removal and debridement in this case.The unique adverse effects observed in this case underscore the importance of tailoring cancer treatment plans to individual patients, taking into account the potential risks associated with immunotherapy in the context of reconstructive surgery.