2020 Volume 69 Issue 2 Pages 274-277
We encountered a case with hemophagocytic macrophages in a peripheral blood smear for the first time in our laboratory. It is believed that such a case is quite rare; however, a report mentioned that the detectability of hemophagocytic macrophages could be increased by an extensive screening method. We subsequently carefully performed investigations considering the possibility of this condition, and we identified four additional cases within five months. Although only one case met the criteria for the diagnosis of hemophagocytic syndrome, all cases showed decreases in the numbers of some types of blood cells during the clinical course. Additionally, bilateral pleural fluid was noted in all five cases; however, its significance is unclear. These findings indicate that the presence of hemophagocytic macrophages in a peripheral blood smear is not very rare. For detection, it is important to carefully investigate the side and feathered edges of a blood smear, especially in cases showing decreases in the numbers of some types of blood cells and in those presenting clinical features of possible hemophagocytic syndrome.
