Pancytopenia

Differential diagnosis

Bone marrow

Immunology

Hemophagocytic lymphohistiocytosis

Histiocyte

Medicine

Disease

Hemophagocytosis

Pathology

Mayo Clinic Proceedings Innovations Quality & Outcomes

Hemophagocytosis refers to ingestion of hematopoietic elements or mature blood cells by another cell, typically by cells conventionally associated with phagocytic capacity. Although the finding of hemophagocytosis as a prominent feature in a patient's bone marrow might prompt consideration of a hemophagocytic syndrome (HPS) such as hemophagocytic lymphohistiocytosis (HLH) in a clinician's or pathologist's differential diagnosis, this morphologic feature can be nonspecific in the absence of other clinical and laboratory features of pathologic immune activation, which is the sine qua non of HPS/HLH. We describe three patients whose clinical presentations included transfusion-dependent anemia and whose bone marrow aspirates showed unexpectedly brisk hemophagocytosis of mature red blood cells. Despite striking morphologic hemophagocytosis, no patient met criteria for diagnosis of an HPS. Transfusion-associated hemophagocytosis and hyperferritinemia must be carefully distinguished from HLH through clinical and laboratory assessment. Biomarkers of pathologic immune activation are important diagnostic aids.

Post-Transfusion Hemophagocytosis Without Hemophagocytic Lymphohistiocytosis