Cytomorphology of familial hemophagocytic syndrome

Serous fluid cytology as a means of detecting hemophagocytosis in Epstein-Barr virus-induced autoimmune hemolytic anemia

The case of a 22-yr-old male who after a brief febrile episode developed autoimmune hemolytic anemia and right pulmonary infiltrate with pleural effusion is presented. Cytologic examination of the pleural fluid revealed lymphocytosis and hemophagocytosis, primarily of red blood cells (RBCs) by mature histiocytes. There was accompanying splenomegaly, laboratory evidence of hepatic dysfunction, and retroperitoneal lymphadenopathy. Besides profound reduction of red blood cells in the peripheral blood, there was reduction of lymphocytes and platelets. As a neoplastic process was ruled out by bone marrow and pleural biopsies, the disease was considered to be virus-induced and was halted and progressively regressed with early institution of vigorous antiinflammatory therapy with adrenocortical steroids. Upon reviewing the case, examination of the bone marrow biopsy disclosed limited hemophagocytosis of RBCs and lymphocytes by histiocytes and considerable viral cytopathic effect on hematopoietic cells (red and white cell precursors and megakaryocytes), which by appropriate immunolabelling was identified as induced by Epstein-Barr virus. A virus-related acquired hemophagocytic syndrome in its early stages was probably present, yet an undesirable clinical outcome was averted by early institution of vigorous steroid therapy. The need to recognize early hemophagocytic changes in cytologic specimens for early institution of appropriate therapy is emphasized. The possibility of erythrophagocytosis, also manifested during the course of an autoimmune hemolytic process and unrelated to hemophagocytic syndrome, is discussed.