Abstract
Large, usually single inclusions, having the staining properties of Heinz-bodies and occurring spontaneously in thalassemic cells, are described. Their frequency is greatest in the normoblasts, either circulating ones or those found in the bone marrow, and decreases sharply in more mature red cells. Splenectomy unmasks this inclusion phenomenon to a large extent. Some staining and other properties of these inclusion bodies are described. It is concluded that these inclusions represent precipitated hemoglobin, very likely uncombined α-chains. The findings are discussed and related to present-day knowledge on hemoglobin synthesis and erythrocyte turnover in thalassemia.