Central Nervous System Involvement in Adult-Onset Hemophagocytic Lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease marked by high cytokine levels, uncontrolled lymphocyte, and macrophage proliferation. It is generally a systemic disorder with varying degrees of central nervous system (CNS) involvement, with the vast majority of cases affecting children. We report a case of CNS-HLH in a 51-year-old male who initially presented with fevers, night sweats, fatigue, bilateral arthralgia, and altered mental status. Computed tomography (CT) of the chest, abdomen, and pelvis showed hepatosplenomegaly. Magnetic resonance imaging (MRI) of the brain showed enhancing lesions mainly in the right frontal lobe with a small hemorrhagic focus. An extensive workup for infectious, autoimmune, and neoplastic and genetic etiologies was only significant for cytopenia with markedly elevated C-reactive protein (CRP), ferritin, and lactate dehydrogenase (LDH), in addition to mild triglyceridemia. Bone marrow and liver biopsy revealed hemophagocytosis. Brain biopsy revealed no evidence of malignancy or infection. The patient was treated with high-dose dexamethasone and etoposide and fully recovered with resolution of all of HLH parameters and decrease/resolution of brain lesion. Clinicians should have a high index of suspicion for CNS-HLH in adults who present with sepsis-like illness with fevers, altered mental status, and cytopenia but negative cultures and unusual radiographic cerebral abnormalities so that early diagnosis and treatment can be initiated to prevent end-organ failure and death.