We discuss a rare but important complication of immunotherapy, and why the usual sepsis workup can send you in the wrong direction.
Case Presentation
A 58-year-old woman on pembrolizumab for metastatic melanoma developed persistent fever, cytopenias and a ferritin above 10,000. Blood cultures were repeatedly negative.
Discussion
HLH secondary to checkpoint blockade is uncommon but increasingly reported. An HScore well above threshold, with a soaring ferritin and no identified organism, should prompt early haematology involvement.
