Hemophagocytic Lymphohistiocytosis Secondary to Prostatic Adenocarcinoma.

Hemophagocytic lymphohistiocytosis (HLH) is caused by excessive immune activation. It can be primary in the setting of genetic defects or secondary in the setting of infection, inflammation, and malignancy. Here we present the fourth reported case of secondary HLH in association with prostatic adenocarcinoma and the diagnostic challenges of this rare, life-threatening condition. This is a 78-year-old male who presented to the hospital with fever and generalized weakness for three days and found to have splenomegaly, pancytopenia, markedly elevated transaminases, and ferritin. Bone marrow biopsy revealed hemophagocytes. He underwent an extensive evaluation to identify the etiology. Para-aortic lymph node biopsy was consistent with prostatic adenocarcinoma. The diagnosis of HLH needs a high index of suspicion because the presentation is nonspecific. HLH is a rapidly progressive and potentially fatal condition underscoring the need for a prompt evaluation if this condition is suspected.