Multifactorial risk analysis of bone marrow histiocytic hyperplasia with hemophagocytosis in critically ill medical patients--a postmortem clinicopathologic analysis.

Objective: Systematic studies of the prevalence and risk factors of histiocytic hyperplasia with hemophagocytosis (HHH) in critically ill patients are lacking. The aim of our study was a) to determine the frequency and intensity of HHH in the bone marrow of patients who died on the medical intensive care unit; b) to analyze morphologic bone marrow changes; and c) to identify possible risk factors and their interactions in the pathogenesis of HHH.

Design: A retrospective observational analysis of clinical data and autopsy findings including histologic and immunohistological analysis of bone marrow to characterize cellularity, siderosis, hemophagocytosis, and T-cell infiltrates.