Poikilocytosis Information and Courses from MediaLab, Inc.

Many of the distorted erythrocytes displayed on the previous page are also present on this one. We see anisocytosis, poikilocytosis, fragmented forms, target cells, and a few Howell-Jolly bodies. Note also circulating nucleated red blood cells (normoblasts). The presence of these normoblasts may represent a premature release from a hyperplastic marrow or, more likely, are due to a lessening of the normal inhibition of erythroid release from the marrow as a result of splenectomy, permitting their earlier entry into the circulation.

Rouleaux and autoagglutination are considered forms of poikilocytosis, but differ from the forms discussed previously because groups of cells are involved rather than single forms. In addition, these types must be differentiated from similar-appearing artifacts caused by improperly made slides and/or examining morphology in an area which is too thick.

Poikilocytosis is a general term used to describe variations in shape. Practically, however, this term has little meaning since cells varying in shape must be specifically identified to be of diagnostic value to the clinician.The work of the French hematologist, Marcel Bessis, with the scanning electron microscope has significantly increased our understanding of the various unusual shapes erythrocytes may assume and their associated pathophysiology.