Preoperative pembrolizumab‑induced hemophagocytic lymphohistiocytosis in a patient with breast cancer: A case report

Abstract

Recently, the anti‑programmed cell death protein 1 antibody pembrolizumab, a type of immune check‑ point inhibitor (ICI), has been used in preoperative systemic chemotherapy for hormone receptor and human epidermal growth factor 2‑negative breast cancer, also known as triple‑negative breast cancer (TNBC). Chemotherapy with pembrolizumab has demonstrated clinical activity in terms of pathologic complete response and event‑free survival. Despite their efficacy, the current understanding of the full spectrum of side effects associated with relatively new ICIs remains incomplete. The present study describes a case of severe pembrolizumab‑induced hemophagocytic lymphohistiocytosis in a patient with early‑stage TNBC, and the strategies used to manage the patient in light of their pathophysiology.