Malignancy-associated hemophagocytic lymphohistiocytosis in adults: Relation to hemophagocytosis, characteristics, and outcomes

BACKGROUND: Malignancy-associated hemophagocytic lymphohistiocytosis (HLH) in adults is a highly lethal disorder. Knowledge gaps have resulted in under diagnosis or delayed diagnosis. METHODS: The University of Texas MD Anderson Cancer Center pathology database (1991-2014) was retrospectively interrogated for the keywords “hemophagocytosis” and/or “lymphohistiocytosis.” Seventy-seven adult patients were identified. All had an underlying malignancy. Sixteen patients who had insufficient documentation were excluded. RESULTS: The majority of patients who had pathologic evidence of hemophagocytosis/lymphohistiocytosis had an incomplete workup to confirm or refute HLH using the 2004 HLH criteria (HLH-2004; n = 8 variables), which is a common problem in adult HLH. Only 13 of 61 patients (21%) met the HLH-2004 diagnostic criteria based on available retrospective data. To identify potentially missed cases of HLH, the published literature was reviewed, and selected additional variables known to be associated with adult HLH were selected, resulting in extended diagnostic criteria of 18 variables. Thirty-five patients met the extended criteria, and 33 had follow-up data available. The median overall survival of the 13 patients who met both the extended criteria and the HLH-2004 criteria was similar to that of the 20 patients who met the extended criteria but NOT the HLH-2004 criteria (1.43 vs 1.76 months, respectively; P =.34) indicating a similar underlying, aggressive, systemic process. Twenty-six patients did not meet either criteria, and 17 had follow-up data available. The median overall survival of the 17 patients who had pathologic hemophagocytosis or lymphohistiocytosis but met neither criteria was significantly superior to the survival of those who met both the extended criteria and the HLH-2004 criteria and those who met the extended criteria but not the HLH-2004 criteria (17.27 vs 1.43 vs 1.76, respectively; P =.002). CONCLUSIONS: The addition of diagnostic laboratory variables that are more easily and rapidly available in smaller institutions and primary care settings than the HLH-2004 variables may be a good surrogate to raise early suspicion of malignancy-associated HLH. Prospective validation is warranted. Cancer 2016.