UC Irvine

BACKGROUND: Hemophagocytic lymphohistiocytosis is a disease process characterized by unregulated hyperactivation of the immune system associated with multiorgan involvement and high mortality rates. Early recognition is crucial and a recently validated diagnostic schema, the H-Score, may facilitate diagnosis particularly in secondary hemophagocytic lymphohistiocytosis cases. We present a patient with secondary hemophagocytic lymphohistiocytosis in association with metastatic renal cell carcinoma in whom high-dose steroid therapy induced a remarkable response. CASE PRESENTATION: A 35-year-old Vietnamese man with quiescent systemic lupus erythematosus was diagnosed 5 months prior to admission with left-sided renal cell carcinoma metastatic to the pancreas and spine. Ten days prior to admission, a febrile illness (temperatures to 39 °C) associated with flu-like symptoms unresponsive to levofloxacin developed. He took only two doses of pazopanib prior to admission. High fevers unresponsive to antimicrobial therapy, cytopenias, disseminated intravascular coagulation, and progressive multiorgan failure led to intubation and intensive care unit stay. Extensive infectious disease workup showed only negative results, but elevation of interleukin-2 receptor, exceedingly high ferritin levels and other features earned an H-Score of 302, consistent with >99% diagnostic probability for secondary hemophagocytic lymphohistiocytosis. High-dose steroid therapy produced a rapid clinical and biochemical response. CONCLUSIONS: Hemophagocytic lymphohistiocytosis is a life-threatening disorder which is likely to be under-recognized. Increased awareness of this disease entity and its diagnosis is crucial toward early recognition and treatment. To our knowledge, our patient is only the second reported with secondary hemophagocytic lymphohistiocytosis occurring in the setting of renal cell carcinoma.