Teardrop-shaped red cells in autoimmune hemolytic anemia.

The presence of teardrop-shaped red cells in peripheral blood has traditionally been felt to reflect altered marrow architecture, namely myelofibrosis. We evaluated two patients with splenomegaly, moderately severe hemolytic anemia due to warm-reactive IgG anti-red cell autoantibody, and bone marrow erythroid hyperplasia without myelofibrosis. A striking predominance of teardrop-shaped red cells was noted upon examination of their blood films. Removal of a spleen containing extramedullary hematopoiesis in one and resolution of splenomegaly in the other were accompanied by disappearance of these cells. Our observations support a role for the spleen and for extramedullary hematopoiesis in the pathogenesis of this distinctive red cell morphologic abnormality.