Prostate Cancer and Reactive Haemophagocytic Lymphohistiocytosis.

We report the case of a 76-year-old man presenting with reactive haemophagocytic lymphohistiocytosis (rHLH) in the setting of disseminated prostate cancer. This often fatal syndrome must be diagnosed early in order to maximize survival. Treatment should be initiated whenever the clinical diagnosis is suspected, even if the HLH-2004 criteria are not met. The HScore is a useful diagnostic tool for rHLH. In case of neurological symptoms, an extensive assessment must be performed. The goal of this case report is to raise awareness of this rare syndrome among oncologists. LEARNING POINTS: The association of prostate cancer and reactive haemophagocytic lymphohistiocytosis (rHLH) has rarely been described.This often fatal syndrome must be recognized early in order to start specific treatment and maximize survival.Specific treatment for rHLH must be accompanied by treatment of the triggering factors. © EFIM 2021.