Bone marrow histiocytic hyperplasia and hemophagocytosis with pancytopenia in typhoid fever.

Typhoid fever was associated with pancytopenia in five patients. Bone marrow examinations revealed histiocytic hyperplasia with marked phagocytosis of platelets, leukocytes, and red blood cells in these individuals. This phagocytosis may contribute to the pancytopenia that occurs in some patients with typhoid fever. The striking degree of the histiocytic hemophagocytosis is reminiscent of the malignant disease, histiocytic medullary reticulosis. The importance of careful exclusion of infectious etiologies in illnesses involving marrow histiocytic proliferation is emphasized.