To describe a case of adult onset, secondary hemophagocytic lymphohistiocytosis (HLH), with neurological manifestations.

HLH is a rare immune disorder, most often observed in children, involving macrophage hyperactivation and subsequent systemic inflammation. In adults, secondary HLH can be seen with infection, malignancy and autoimmune disorders.

A 69 year old male with a 40 pound weight loss over the previous four months was transferred from an outside hospital for further evaluation of a 1 week history of fever, as high as 103 Fahrenheit, fatigue, chills and productive cough. Papular skin lesions that developed into ulcerative areas were noted, skin biopsy was consistent with pyoderma gangrenosum. He was treated for community acquired pneumonia with a suspected myelodysplastic syndrome based on profound anemia (Hgb 7.5) and thrombocytopenia (platelets 10,000). Bone marrow biopsy and peripheral blood analysis demonstrated aberrant increased myeloblasts along with hemophagocytosis. Ferritinemia with >36,000 ng/ml was present. The patient's neurologic examination was generally non focal, however, over the course of treatment he became lethargic. Subsequent brain MRI showed focal areas of restricted diffusion. The patient rapidly deteriorated with CNS, pulmonary, renal, dermatologic and hematologic involvement.  He expired despite a regimen of etoposide and dexamethasone. Secondary hemophagocytic lymphohistiocytosis was diagnosed based on biopsy findings, elevated ferritin, fever and cytopenias.

Secondary HLH is rare condition with a broad and variable presentation. In this case, the patient became encephalopathic with abnormalities on brain MRI, rapid decline and death. The restricted diffusion observed on MRI is consistent with thrombotic infarction, but whether from hypercoagulable state or inflammatory vasculopathy could not be determined. Thrombocytopenia and renal failure are significant barriers to diagnostic work up. Increased awareness and study of HLH is required to promote earlier treatment and ultimately better outcomes.