Hemophagocytosis

Hemophagocytosis is a dangerous form of phagocytosis in which histiocytes engulf red blood cells, white blood cells, platelets, and their precursors^[1] in bone marrow and other tissues.

Micrograph showing hemophagocytosis in the spleen. H&E stain.

It is part of the presentation of hemophagocytic lymphohistiocytosis and macrophage activation syndrome. It has also been seen at autopsy of people who died of COVID-19.^[2]