Tumor Lysis Syndrome following a Single Dose of Nivolumab for Relapsed Small-Cell Lung Cancer.

Tumor lysis syndrome (TLS) is an oncologic emergency most frequently associated with initial treatment of hematologic malignancies and high-tumor burden solid tumors such as small-cell lung cancer (SCLC). Most often, TLS is associated with cytotoxic chemotherapy. In the treatment of SCLC, a paradigm shift has taken place in which immunotherapy is often added to chemotherapy for extensive-stage disease in the frontline setting or as monotherapy in the relapsed setting. Nivolumab is a programmed death 1 receptor blocking antibody previously FDA indicated for the treatment of metastatic SCLC with progression after platinum-based chemotherapy and at least one other line of therapy. Nivolumab, like all immune checkpoint inhibitor therapies, is associated with immune-mediated adverse reactions; however, there are few reported cases of nivolumab-induced TLS. We present a case of nivolumab-induced TLS following a single infusion. An 86-year-old female with a history of widely metastatic SCLC with metastasis to the liver, bone, and lymph nodes presented to the hospital following a fall due to weakness, dizziness, slurred speech, nausea, vomiting, and abdominal pain occurring 6 days after receiving her first nivolumab infusion. After extensive evaluation, the patient was diagnosed with TLS with hyperkalemia, acute renal failure, hyperphosphatemia, and hypocalcemia. She was treated aggressively with intravenous fluids, rasburicase, and sodium polystyrene sulfate (Kayexalate