Elliptocytosis. Light micrograph of red blood cells in a case of elliptocytosis. Red blood cells (erythrocytes) carry oxygen and carbon dioxide to and from body tissues. Elliptocytosis is a hereditary disorder that results in red blood cells with this oval shape, rather than the normal biconcave disc shape. Unless the form of this disorder is severe, treatment is normally not needed. Elliptocytosis can lead to a predisposition to forms of anaemia, gallstones and an enlarged spleen (splenomegaly).