Hemophagocytic Lymphohistiocytosis and Bone Marrow Hemophagocytosis: A 5-Year Institutional Experience at a Tertiary Care Hospital.

OBJECTIVE: The purpose of this study was to correlate the significance of bone marrow hemophagocytosis and analyze outcome data in patients with suspected hemophagocytic lymphohistiocytosis (HLH) at a tertiary care hospital during the course of 5 years.

METHODS: The pathology database of State University of New York Upstate Medical University, Syracuse, was searched for the terms "hemophagocytosis," "hemophagocytic syndrome," and "hemophagocytic lymphohistiocytosis" encompassing the period January 2009-December 2014. Bone marrow aspirate and biopsy specimens, along with ancillary laboratory studies, clinical course, and outcome data, were reviewed for each case.

RESULTS: Of the 23 patients included in our study, HLH was diagnosed in 14 (60.8%). Bone marrow hemophagocytosis (HPC) was seen in a higher proportion of patients (78.5%) who were diagnosed as having HLH; however, 55.5% of the patients who were not diagnosed as having HLH also showed evidence of bone marrow HPC. Patients with malignancy-associated HLH had a markedly worse outcome compared with patients with nonmalignancy-associated HLH.

CONCLUSIONS: Although bone marrow HPC is fairly sensitive, it is not specific to establish a diagnosis of HLH. A high index of clinical suspicion together with early diagnosis and treatment is imperative to improve outcomes in patients suspected of having HLH.